Abstract Purpose RNF213 encodes one of the largest E3 ubiquitin ligases in the human proteome, playing essential roles in ubiquitination, DNA damage repair, and immune system regulation. Although RNF213 has been extensively studied in Moyamoya disease, its involvement in cancer biology remains insufficiently understood. This study seeks to conduct a comprehensive pan-cancer analysis to explore RNF213 expression, mutation characteristics, its correlation with clinical outcomes, and its potential as a prognostic biomarker and a therapeutic target, particularly in the context of immunotherapy. Methods Leveraging data from The Cancer Genome Atlas (TCGA) and additional publicly available datasets, we performed a systematic analysis of RNF213 expression patterns, mutation frequencies, and their relationships with clinical outcomes. We also conducted survival analyses to assess the impact of RNF213 expression on the efficacy of immune checkpoint blockade therapies. Results RNF213 demonstrated variable expression levels across different cancer types, with notable overexpression observed in glioblastoma and endometrial carcinoma, while underexpression was detected in lung adenocarcinoma and prostate adenocarcinoma. Elevated RNF213 expression was linked to unfavorable survival outcomes in acute myeloid leukemia and low-grade glioma, whereas it was associated with better survival in sarcoma and skin cutaneous melanoma. RNF213 expression showed a positive association with immune-related genes and immune cell infiltration, particularly in glioblastoma and breast cancer. Furthermore, patients with high RNF213 expression experienced significant survival advantages when receiving combined anti-PD-1 and anti-CTLA-4 immunotherapies. Conclusion This study highlights RNF213’s dual functionality in tumor progression and immune modulation, underscoring its potential as both a prognostic biomarker and a therapeutic target. The findings suggest that RNF213 may play a pivotal role in determining immunotherapy outcomes, warranting further exploration into its underlying mechanisms and clinical applications. Supplementary Information The online version contains supplementary material available at 10.1007/s12672-025-03237-0. Keywords: RNF213, Pan-cancer analysis, Tumor microenvironment, Immunotherapy, Immune checkpoint blockade, Prognostic biomarker Introduction Cancer is recognized as the second leading cause of death worldwide, with its global burden projected to rise significantly in the coming decades. It is characterized by the uncontrolled proliferation, invasion, and metastasis of cells, with most cancer-related fatalities resulting from metastatic disease [[32]1]. Advances in large-scale parallel sequencing technologies have enabled the systematic identification of genetic alterations across the cancer genome, offering unprecedented insights into the molecular mechanisms underlying tumorigenesis [[33]2–[34]4]. Despite these advancements, the inherent complexity of cancer necessitates a more comprehensive understanding of these mechanisms, which often vary considerably across different cancer types. Pan-cancer analyses, which simultaneously investigate multiple cancer types, provide a unique opportunity to uncover shared pathways and genetic alterations that drive tumorigenesis. Such studies not only deepen our understanding of cancer biology but also aid in identifying novel biomarkers and therapeutic targets. Ring finger protein 213 (RNF213), encoded by a gene located on chromosome 17q25.3, is the largest E3 ubiquitin ligase in the human proteome, with a molecular weight of 591 kDa. It exhibits both ubiquitin ligase and ATPase activities and is involved in various biological processes, including ubiquitination, DNA damage repair, and innate immune responses [[35]5–[36]7]. RNF213 is most prominently associated with Moyamoya disease, a rare cerebrovascular disorder [[37]8, [38]9]. Notably, RNF213 functionally interacts with GUCY1A3, another key gene implicated not only in Moyamoya disease but also in coronary artery disease and pulmonary artery hypertension. Both RNF213 and GUCY1A3 influence lipid metabolism, inflammation mediated by NF-κB, and vascular stability through shared signaling pathways such as calcineurin/NFAT and caveolin. This interplay underscores their critical roles in vascular homeostasis and related pathologies beyond Moyamoya disease, highlighting the importance of investigating their coordinated functions [[39]10]. However, emerging evidence indicates its significant involvement in cancer. For example, alterations in RNF213 have been implicated in the progression of several cancers, such as gliomas, hepatocellular carcinoma, and breast cancer [[40]11–[41]13]. Recurrent RNF213-SLC26A11 fusion transcripts have been identified in gliomas and myeloid leukemia [[42]11, [43]14]while RNF213 mutations have been reported in oral tongue squamous cell carcinoma, ovarian cancer, advanced gastric cancer, and gastric cancer with liver metastases [[44]13, [45]15–[46]17]. Furthermore, RNF213 expression has been linked to immune cell infiltration and prognosis in lung cancer, particularly non-small cell lung cancer, highlighting its potential role in modulating the tumor immune microenvironment and affecting clinical outcomes [[47]18]. These findings suggest that RNF213 may function as either a tumor suppressor or an oncogene, depending on the specific cancer type and biological context. Additionally, RNF213 has been implicated in the regulation of endoplasmic reticulum (ER) stress responses. Recent studies demonstrated that suppression of RNF213 inhibits ER stress by upregulating SEL1L, a key component of the ER-associated degradation (ERAD) pathway, thereby promoting cellular homeostasis under stress conditions [[48]19]. This suggests a potential link between RNF213 and ER function that may be relevant in both vascular and cancer biology. Despite these discoveries, a comprehensive understanding of RNF213’s role across diverse cancer types remains incomplete. Notably, RNF213 displays varying expression patterns and mutation frequencies across different cancers, and its dysregulation has been linked to aggressive tumor behaviors, including enhanced proliferation, invasion, and metastasis. However, the precise mechanisms through which RNF213 contributes to tumorigenesis are not yet fully elucidated. To address this knowledge gap, this study aims to perform a pan-cancer analysis of RNF213 expression and mutation patterns using publicly available datasets, such as TCGA and other large-scale genomic resources. By systematically evaluating RNF213’s expression levels, mutation frequencies, and their associations with clinical outcomes across multiple cancer types, this work seeks to clarify its role in cancer progression and assess its potential as a biomarker and therapeutic target. This study lays the groundwork for future research to investigate the functional mechanisms of RNF213 and its implications for cancer biology and treatment strategies. Methods and materials RNF213 expression analysis and protein distribution The mRNA expression levels of RNF213 in normal human tissues, as well as its subcellular protein distribution, were analyzed using data from the Human Protein Atlas (HPA) database ([49]https://www.proteinatlas.org). To evaluate RNF213 expression across various cancer types, we utilized the TCGA TARGET GTEx dataset (PANCAN, N = 19131, G = 60499) available through the UCSC Xena database ([50]https://xenabrowser.net/). Expression data for RNF213 (ENSG00000173821) were retrieved from samples categorized as Solid Tissue Normal, Primary Solid Tumor, Primary Tumor, Normal Tissue, Primary Blood Derived Cancer - Bone Marrow, and Primary Blood Derived Cancer - Peripheral Blood. To ensure data quality, samples with expression levels of 0 were excluded. The expression values were normalized using a log2(x + 1) transformation. Cancer types with fewer than three samples were removed, resulting in data from 34 distinct cancer types. For subcellular localization analysis, indirect immunofluorescence (IF) staining was performed on A-431, U2OS, and U-251MG cell lines using antibodies obtained from Atlas Antibodies and Sigma-Aldrich (Catalog numbers HPA003347 and HPA026790). Cells were fixed with paraformaldehyde (PFA) and stained at a dilution of 1:50. The antibody specificity and staining patterns were validated by the Human Protein Atlas using standard and enhanced validation methods, including siRNA knockdown, GFP-tagged cell lines, and independent antibodies. Confocal microscopy was used to visualize RNF213 localization, with co-staining for microtubules and ER markers. Genomic alterations and expression correlation analysis Genomic alterations of RNF213 were examined using the cBioPortal platform ([51]https://cbioportal.org). RNA-seq data for tumor cell lines were obtained from the Cancer Cell Line Encyclopedia (CCLE) ([52]https://sites.broadinstitute.org/ccle/). The relationship between copy number variations (CNVs) and RNF213 mRNA expression was analyzed using the Gene Set Cancer Analysis (GSCA) platform ([53]https://guolab.wchscu.cn/GSCA/). RSEM-normalized mRNA expression data and CNV data were downloaded from the TCGA database and merged using TCGA barcodes. Spearman correlation analysis was conducted to evaluate the association between RNF213 mRNA expression and CNVs, with p-values adjusted using the false discovery rate (FDR) [[54]20]. RNF213 expression and prognostic significance The association between RNF213 expression and tumor staging was analyzed using the Gene Expression Profiling Interactive Analysis database (GEPIA2; [55]http://gepia.cancer-pku.cn/), a web server that enables analysis of RNA sequencing expression data from 9,736 tumors and 8,587 normal samples derived from TCGA and the GTEx projects, providing a standardized processing pipeline for high-resolution exploration of gene expression patterns. RNF213 expression data were extracted from the TCGA Pan-Cancer dataset available through the UCSC Xena database. Samples with expression levels of 0 and cancer types with fewer than three samples were excluded. Expression values were transformed using log2(x + 0.001). Differential expression analysis across clinical stages was performed using R software (version 3.6.4). Statistical significance was determined using the unpaired Student’s t-test for pairwise comparisons and analysis of variance (ANOVA) for multiple group comparisons. For survival analysis, overall survival (OS) and disease-free survival (DFS) data were obtained from GEPIA2. Patients were divided into high and low RNF213 expression groups based on the top 50% and bottom 50% expression thresholds. Kaplan-Meier survival curves were generated, and the log-rank test was used to assess statistical significance. Additionally, Cox proportional hazards regression models were constructed using the coxph function from the R package survival (version 3.2-7) to evaluate the relationship between RNF213 expression and prognosis. Immunoregulatory gene analysis To explore the association between RNF213 and immune pathways, RNF213 expression data and 150 marker genes representing five immune pathway categories (chemokines, receptors, MHC molecules, immunoinhibitors, and immunostimulators) were extracted from the TCGA Pan-Cancer dataset. Expression values were log2(x + 0.001) transformed, and Pearson correlation coefficients were calculated between RNF213 and the marker genes. Tumor stemness scores (RNAss), derived from mRNA features, were integrated with RNF213 expression data to assess the relationship between tumor stemness and RNF213 expression [[56]21]. Pearson correlation coefficients were computed for 37 cancer types. Immune infiltration analysis Immune infiltration scores were calculated using the ESTIMATE algorithm in R. Stromal, immune, and ESTIMATE scores were computed for 9554 tumor samples across 39 tumor types [[57]22]. Pearson correlation coefficients were calculated between RNF213 expression and immune infiltration scores. Additionally, immune cell infiltration scores for B cells, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells were reassessed using the TIMER method from the R package IOBR [[58]23, [59]24]. Spearman correlation coefficients were calculated to determine the relationship between RNF213 expression and immune cell infiltration across 9405 tumor samples in 36 tumor types. RNF213-associated gene analysis Experimentally validated RNF213 binding proteins were retrieved from the STRING database ([60]https://cn.string-db.org/). The top 100 genes associated with RNF213 were identified using the “Similar Genes Detection” module in GEPIA2. Expression data for the top 10 target genes were obtained from TIMER2.0, a comprehensive web resource designed for systematic analysis of immune cell infiltrates across diverse cancer types. TIMER2.0 estimates immune cell abundances using multiple deconvolution methods and allows dynamic generation of high-quality figures to explore tumor immunological, clinical, and genomic features. Expression data were visualized as heatmaps. Functional enrichment analysis was performed using the R package clusterProfiler (version 3.14.3) with KEGG Pathway and Gene Ontology (GO) annotations. Gene sets with a minimum size of 5 and a maximum size of 5000 were included, and statistical significance was defined as P < 0.05 and FDR < 0.01. Visualization of enrichment results was conducted using the Sangerbox3.0 platform ([61]http://sangerbox.com/home.html). RNF213 expression and prognosis in cancer immunotherapy The prognostic value of RNF213 expression in patients undergoing immune checkpoint blockade (ICB) therapies, including anti-PD-1, anti-PD-L1, and anti-CTLA-4 treatments, was evaluated using the Kaplan-Meier Plotter. Patients were stratified into high and low RNF213 expression groups, and median OS was compared using the log-rank test. RNF213 expression and mutation patterns were further analyzed using the Tumor Immune Syngeneic Mouse (TISMO) database, which includes both in vivo and in vitro datasets. Differential expression analysis was performed using DESeq2, with RNF213 expression quantified as log-transformed transcripts per million (log(TPM)) values. Statistical significance thresholds were set at *FDR ≤ 0.05, **FDR ≤ 0.01, and ***FDR  ≤ 0.001. Statistical analysis Statistical analyses were conducted using R software and specified bioinformatics tools. Differential RNF213 expression across tumor stages was evaluated via unpaired t-test (pairwise) or ANOVA (multi-group). Spearman correlation with false discovery rate (FDR) adjustment assessed associations between RNF213 mRNA expression and copy number variations. Survival outcomes (OS/DFS) were analyzed using Kaplan-Meier curves (log-rank test) and Cox regression. Correlations with immune markers, tumor stemness (RNAss), and immune infiltration scores (ESTIMATE/TIMER) were calculated via Pearson/Spearman methods. Functional enrichment of RNF213-associated genes was performed using clusterProfiler (KEGG/GO; P < 0.05, FDR < 0.01). For immunotherapy cohorts, DESeq2-based differential expression and survival analyses (log-rank test) were applied with FDR-defined significance levels (*≤0.05, **≤0.01, ***≤0.001). Statistical significance was set at P < 0.05 unless otherwise noted. Results Differential expression and genomic alterations of RNF213 in normal and tumor tissues To explore the potential role of RNF213 in cancer, its mRNA expression levels were first analyzed across normal human tissues. The results demonstrated that RNF213 is broadly expressed, with particularly high expression levels observed in the parathyroid, bone marrow, thymus, spleen, appendix, lymph nodes, tonsils, lungs, retina, stomach, thyroid, bladder, salivary glands, small intestine, gallbladder, and kidneys (nTPM > 10) (Fig. [62]1A). Fig. 1. [63]Fig. 1 [64]Open in a new tab RNF213 mRNA expression and protein localization in normal tissues and cancer types. A RNF213 mRNA expression levels across normal human tissues, showing widespread expression with notably high levels in specific tissues. B Differential expression of RNF213 mRNA in tumor and normal tissues across various cancer types, highlighting significant upregulation or downregulation in specific cancers. C Subcellular localization of RNF213 protein in cancer cell lines. Immunofluorescence images show RNF213 colocalized with microtubules and endoplasmic reticulum (ER) in A-431, U2OS, and U-251MG cells. Separate merged images of RNF213 with microtubules and RNF213 with ER are provided to illustrate predominant localization Next, RNF213 mRNA expression was evaluated in various tumor types using data from the TCGA and GTEx databases. The analysis revealed significant upregulation of RNF213 mRNA in multiple cancers, including glioblastoma (GBM), glioma (GBMLGG), low-grade glioma (LGG), endometrial carcinoma (UCEC), invasive breast carcinoma (BRCA), cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), esophageal carcinoma (ESCA), stomach and esophageal carcinoma (STES), kidney renal papillary cell carcinoma (KIRP), kidney cancer (KIPAN), stomach adenocarcinoma (STAD), head and neck squamous cell carcinoma (HNSC), kidney renal clear cell carcinoma (KIRC), hepatocellular carcinoma (LIHC), bladder urothelial carcinoma (BLCA), rectal adenocarcinoma (READ), pancreatic adenocarcinoma (PAAD), testicular germ cell tumors (TGCT), acute lymphoblastic leukemia (ALL), acute myeloid leukemia (LAML), and cholangiocarcinoma (CHOL). Conversely, RNF213 mRNA was found to be significantly downregulated in cancers such as lung adenocarcinoma (LUAD), prostate adenocarcinoma (PRAD), lung squamous cell carcinoma (LUSC), Wilms tumor (WT), thyroid carcinoma (THCA), uterine carcinosarcoma (UCS), adrenocortical carcinoma (ACC), and kidney chromophobe (KICH). For other tumor types, including colon adenocarcinoma (COAD), colorectal adenocarcinoma (COADREAD), skin cutaneous melanoma (SKCM), ovarian serous cystadenocarcinoma (OV), and pheochromocytoma and paraganglioma (PCPG), no significant differences in RNF213 expression were observed (Fig. [65]1B). In the context of pan-cancer analysis, immunofluorescence was employed to investigate the subcellular localization of RNF213 protein in A-413, U2OS, and U-251MG cell lines. Separate merged images of RNF213 with microtubules and RNF213 with ER were obtained, demonstrating that RNF213 predominantly localizes to the ER and microtubules (Fig. [66]1C). Genomic alterations and correlation analysis of RNF213 Using the cBioPortal platform, we analyzed the genomic alterations of RNF213 across multiple cancer types. Among the detected alterations, mutations were the most prevalent, followed by gene amplifications (Fig. [67]2A). Further investigation using the GSCA platform demonstrated significant positive correlations between RNF213 CNVs and mRNA expression levels in various cancers (FDR ≤ 0.05). Notable correlations were observed in ACC (Spearman’s ρ = 0.384, FDR = 0.006), BRCA (Spearman’s ρ = 0.367, FDR < 0.0001), KICH (Spearman’s ρ = 0.378, FDR = 0.034), LUAD (Spearman’s ρ = 0.304, FDR < 0.0001), OV (Spearman’s ρ = 0.327, FDR < 0.0001), and SKCM (Spearman’s ρ = 0.303, FDR < 0.0001). Fig. 2. [68]Fig. 2 [69]Open in a new tab Genomic alterations and CNV-mRNA expression correlation of RNF213 across cancer types. A Summary of genomic alterations of RNF213 across various cancer types, showing mutations as the most frequent alteration, followed by amplifications. B Correlation analysis between RNF213 CNVs and mRNA expression in different cancer types. C Positive correlation between RNF213 amplification and mRNA expression levels, highlighting the impact of CNV on gene expression Additional significant correlations were identified in COAD (Spearman’s ρ = 0.245, FDR < 0.001), LIHC (Spearman’s ρ = 0.249, FDR < 0.0001), and UCEC (Spearman’s ρ = 0.286, FDR < 0.001). Conversely, no significant correlations were found in certain cancer types, such as diffuse large B-cell lymphoma (DLBC, FDR = 1) and LAML (FDR = 1). While a few cancer types displayed negative correlations, these were not statistically significant (Fig. [70]2B). Furthermore, analysis of RNF213 amplifications revealed a strong positive relationship between CNV levels and mRNA expression, further supporting the role of CNVs in regulating RNF213 expression (Fig. [71]2C). Correlation of RNF213 expression with tumor staging and survival outcomes The analysis of RNF213 expression across various tumor stages revealed significant associations that differed depending on the cancer type. In PAAD, OV, and SKCM, RNF213 expression was inversely correlated with clinical staging, indicating that higher RNF213 expression levels might be linked to earlier stages of these cancers (Fig. [72]3A–C). Further validation using data from the UCSC database supported these observations and identified a positive correlation between RNF213 expression and clinical staging in KIPAN. These findings suggest that RNF213 may have distinct roles in tumor biology, potentially functioning as a tumor suppressor in cancers such as PAAD and OV, while promoting tumor progression in kidney-related malignancies (Fig. [73]3D). Fig. 3. [74]Fig. 3 [75]Open in a new tab Correlation of RNF213 expression with tumor stage and survival outcomes. A–D Correlation between RNF213 expression and clinical staging across different cancer types. E–I Association of RNF213 expression with OS in selected cancer types. J, K Association of RNF213 expression with DFS in specific cancer types Survival analysis provided additional insights into the prognostic significance of RNF213, highlighting its complex and context-dependent roles. Elevated RNF213 expression was associated with poorer OS in LAML, LGG, and Uveal Melanoma (UVM). In contrast, higher RNF213 expression was linked to improved OS in sarcoma (SARC) and SKCM (Fig. [76]3E–I). Moreover, elevated RNF213 expression was found to correlate with reduced DFS in LGG and UVM, underscoring its potential as a context-specific prognostic marker (Fig. [77]3J, K). These results suggest that RNF213 could serve as a valuable biomarker for predicting survival outcomes in certain cancer types. To better understand the association between RNF213 expression and prognosis in various cancers, we analyzed standardized pan-cancer datasets and corresponding follow-up data from the UCSC database. Using the R package “survival” and the Cox proportional hazards regression model (coxph function), we conducted statistical significance testing through the log-rank test. The results indicated that elevated RNF213 expression was significantly correlated with poor prognosis in seven cancer types, including TCGA-GBMLGG(N = 619, p = 2.9e-4, HR = 1.44(1.18, 1.76)), TCGA-LGG(N = 474, p= 5.2e-7, HR = 2.19(1.62, 2.97)), TARGET-LAML(N = 142, p = 1.2e-4, HR = 1.46(1.20, 1.78)), TCGA-KIRP(N = 276, p = 4.3e-3, HR = 1.92(1.23, 3.00)), TCGA-KIPAN(N = 855, p = 3.0e-4, HR = 1.32(1.14, 1.54)), TCGA-UVM(N = 74, p = 3.7e-3, HR = 2.38(1.31, 4.32)) and TCGA-LAML(N = 209, p = 6.2e-3, HR = 1.27(1.07, 1.52)). Conversely, reduced RNF213 expression was associated with unfavorable prognosis in four cancer types, namely TCGA-SARC(N = 254, p = 0.01, HR = 0.70(0.53, 0.93)), TCGA-SKCM(N = 444, p = 3.1e-7, HR = 0.66(0.56, 0.77)), TCGA-SKCM-M(N = 347, p = 4.7e-6, HR = 0.66(0.56, 0.79)) and TARGET-ALL(N = 86, p = 8.4e-3, HR = 0.75(0.61, 0.93)) (Fig. [78]4). Fig. 4. [79]Fig. 4 [80]Open in a new tab Prognostic associations of RNF213 expression. Forest plot of Cox hazard ratios (HR) across 44 cancer datasets, highlighting 11 tumors with significant associations (p < 0.05) Immunomodulatory role of RNF213 in various cancer types To investigate the immunomodulatory role of RNF213 in tumors, we analyzed its association with immune regulatory genes, immune checkpoints, tumor stemness scores, and immune infiltration. Using a pan-cancer dataset from the UCSC database, we retrieved expression data for the RNF213 gene and 150 marker genes related to five immune pathways: chemokines (41 genes), receptors (18 genes), MHC molecules (21 genes), immune inhibitors (24 genes), and immune stimulators (46 genes). Pearson correlation coefficients were calculated to evaluate the relationship between RNF213 expression and these immune pathway marker genes. The analysis revealed a positive correlation between RNF213 expression and the majority of immune regulatory genes (Fig. [81]5A). Fig. 5. [82]Fig. 5 [83]Open in a new tab Correlation of RNF213 expression with immune regulatory pathways and immune checkpoints. A Correlation between RNF213 expression and marker genes of five immune pathways, including chemokines, receptors, MHC molecules, immune inhibitors, and immune stimulators. B Association of RNF213 expression with immune checkpoints, including inhibitory and stimulatory checkpoints, across cancer types. C Differential correlation of RNF213 expression with immune checkpoints in specific cancer types We further explored the relationship between RNF213 and specific immune checkpoints, including 24 inhibitory and 36 stimulatory checkpoints. The results demonstrated significant correlations between RNF213 expression and most immune checkpoints (Fig. [84]5B). A detailed analysis revealed that RNF213 expression was significantly associated with immune checkpoints in 22 cancer types. Specifically, RNF213 showed a significant positive correlation in four cancers, including BRCA(N = 1080)(R = 0.069, P = 0.024), STES(N = 578)(R = 0.113, P = 0.007), STAD(N = 399)(R = 0.124, P = 0.013) and PCPG(N = 176)(R = 0.172, P = 0.022), while exhibiting a significant negative correlation in 18 cancers, such as GBM(N = 152)(R=-0.278, P = 0.001), GBMLGG(N = 659)(R=-0.361,P = 9.811), LGG(N = 507)(R=-0.476, P = 5.400e-30), CESC(N = 301)(R=-0.129, P = 0.026), COAD(N = 281)(R=-0.194, P = 0.001), COADREAD(N = 369)(R=-0.204, P = 0.00008), LAML(N = 167)(R=-0.230, P = 0.003), KIRP(N = 283)(R=-0.233, P = 0.00007), KIPAN(N = 860)(R=-0.332, P = 1.358e-23), HNSC(N = 512)(R=-0.088, P = 0.046), KIRC(N = 512)(R=-0.223, P = 3.631e-7), LUSC(N = 483)(R=-0.099, P = 0.030), THYM(N = 119)(R=-0.415, P = 0.000003), THCA(N = 499)(R=-0.314, P = 6.596e-13), READ(N = 88)(R=-0.263, P = 0.013), PAAD(N = 156)(R=-0.255, P = 0.001), TGCT(N = 147)(R=-0.319, P = 0.00008) and KICH(N = 65)(R=-0.498, P = 0.00002) (Fig. [85]5C). Correlation between RNF213 expression and immune infiltration across cancer types To investigate the relationship between RNF213 expression and immune infiltration, we analyzed immune infiltration scores from 9554 tumor samples across 39 cancer types. Pearson correlation coefficients were calculated to assess the association between RNF213 expression and immune infiltration scores for each cancer type. Notably, RNF213 expression showed a significant positive correlation with immune infiltration in 30 cancer types, including TCGA-GBMLGG(N = 656, R = 0.27, P = 1.6e-12), TCGA-LGG(N = 504, R = 0.45, P = 5.0e-27), TCGA-CESC(N = 291, R = 0.33, P = 1.2e-8), TCGA-LUAD(N = 500, R = 0.16, P = 4.8e-4), TCGA-COAD(N = 282, R = 0.38, P = 6.4e-11), TCGA-COADREAD(N = 373, R = 0.38, P = 1.9e-14), TCGA-LAML(N = 149, R = 0.39, P = 7.8e-7), TCGA-BRCA(N = 1077, R = 0.18, P = 2.0e-9), TCGA-ESCA(N = 181, R = 0.21, P = 4.0e-3), TCGA-STES(N = 569, R = 0.11, P = 0.01), TCGA-SARC(N = 258, R = 0.34, P = 1.8e-8), TCGA-KIPAN(N = 878, R = 0.20, P = 3.1e-9), TCGA-STAD(N = 388, R = 0.17, P = 7.2e-4), TCGA-PRAD(N = 495, R = 0.22, P = 4.4e-7), TCGA-HNSC(N = 517, R = 0.41, P = 7.1e-22), TCGA-KIRC(N = 528, R = 0.36, P = 1.1e-17), TCGA-LUSC(N = 491, R = 0.20, P = 1.2e-5), TCGA-THCA(N = 503, R = 0.28, P = 3.3e-10), TCGA-READ(N = 91, R = 0.41, P = 6.1e-5), TCGA-SKCM-M(N = 351, R = 0.54, P = 1.7e-28), TCGA-SKCM(N = 452, R = 0.51, P = 1.1e-30), TCGA-PAAD(N = 177, R = 0.35, P = 2.0e-6), TCGA-OV(N = 416, R = 0.32, P = 1.3e-11), TCGA-TGCT(N = 132, R = 0.64, P = 1.1e-16), TCGA-SKCM-P(N = 101, R = 0.29, P = 2.8e-3), TCGA-UVM(N = 79, R = 0.49, P = 3.7e-6), TCGA-UCS(N = 56, R = 0.35, P = 8.0e-3), TCGA-BLCA(N = 405, R = 0.21, P = 1.7e-5), TCGA-KICH(N = 65, R = 0.53, P = 6.9e-6) and TCGA-DLBC(N = 46, R = 0.64, P = 1.4e-6) (Fig. [86]6A–D1). Fig. 6. [87]Fig. 6 [88]Open in a new tab Correlation of RNF213 expression with immune infiltration across cancer types. A–D1 Correlation between RNF213 expression and immune infiltration scores in 39 cancer types, showing significant positive associations in 30 cancer types. E1 Association between RNF213 expression and immune cell infiltration, including B cells, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells, across multiple cancer types To further clarify the association between RNF213 expression and immune cell infiltration, we analyzed data from 9405 tumor samples across 36 cancer types. The results revealed significant correlations between RNF213 expression and immune cell infiltration scores in multiple cancer types. Specifically, RNF213 expression was strongly associated with the infiltration of various immune cell types, including B cells, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells, in certain tumor types. These findings suggest that RNF213 may play a critical role in modulating the tumor immune microenvironment across diverse cancer types (Fig. 6E1). Analysis of RNF213-associated genes Using the STRING online tool, we identified a total of 50 proteins that interact with RNF213 (Fig. [89]7A, Supplementary Table [90]1). Notably, among the identified RNF213-interacting proteins, PTPN1 (also known as PTP1B) was included, consistent with previous studies demonstrating a functional relationship between PTP1B and RNF213 in regulating tumor survival under hypoxia [[91]12]. This finding supports the reliability of our network analysis and suggests that the PTP1B-RNF213 axis may play a critical role in cancer biology. Furthermore, recent work by Bhardwaj et al. has elucidated a mechanism involving PTP1B and RNF213 in hypoxia-induced inflammatory cell death, further underscoring the biological relevance of this interaction [[92]25]. Additionally, the GEPIA2 platform was utilized to determine the top 100 genes associated with RNF213 (Supplementary Table [93]2). Among these genes, the top 10 exhibited a strong positive correlation with RNF213 expression across multiple cancer types (Fig. [94]7B). To better understand the functional roles of these genes, we conducted KEGG and GO enrichment analyses. Fig. 7. [95]Fig. 7 [96]Open in a new tab Protein–protein interaction network, associated genes, and functional enrichment analysis of RNF213. A Protein–protein interaction (PPI) network of RNF213. B Correlation analysis of RNF213-associated genes across cancer types. C KEGG pathway enrichment analysis of RNF213-associated genes. D GO enrichment analysis of RNF213-associated genes The KEGG pathway analysis identified several pathways significantly linked to RNF213, shedding light on its potential involvement in tumorigenesis and cancer progression. The enriched pathways included “NOD-like receptor signaling pathway,” “Epstein-Barr virus infection,” and “Necroptosis,” which are associated with key processes such as immune evasion, modulation of the tumor microenvironment, and inflammation-driven cancer development (Fig. [97]7C). GO enrichment analysis revealed that the top 100 RNF213-associated genes were significantly enriched in various biological processes (BP). These processes included “defense response to virus,” “innate immune response,” “immune response,” and “response to interferon-gamma.” The enrichment of these immune-related pathways highlights RNF213’s potential role in immunoregulation and antiviral responses, suggesting a possible link between its immune functions and cancer progression (Fig. [98]7D). RNF213 expression and its impact on immunotherapy outcomes Analysis of RNF213 expression using Kaplan-Meier Plotter demonstrated its significant effect on OS across different immunotherapy subtypes. In patients who did not undergo ICB therapy, high RNF213 expression was associated with a reduced median OS of 12.81 months, compared to 20 months in the low expression group (P = 0.0014, FDR = 10%) (Fig. [99]8A). This suggests that elevated RNF213 expression negatively impacts survival when immunotherapy is not used. Fig. 8. [100]Fig. 8 [101]Open in a new tab Impact of RNF213 expression on immunotherapy outcomes and cytokine responses. A–E Kaplan–Meier survival analysis of RNF213 expression in patients receiving different immunotherapy regimens, including no immunotherapy, anti-PD-1, anti-PD-L1, anti-CTLA-4, and combined anti-PD-1/anti-CTLA-4 therapies. RNF213 expression shows varying effects on overall survival (OS) depending on the treatment context. F Changes in RNF213 expression in response to immune checkpoint blockade (ICB) therapy across multiple tumor models, highlighting its upregulation in responders in melanoma, colorectal cancer, head and neck squamous cell carcinoma, and breast cancer models, with context-dependent effects observed in gastric adenocarcinoma. G Upregulation of RNF213 expression following cytokine treatments (IFNβ, IFNγ, and TNFα) in multiple cancer cell lines, including breast cancer, melanoma, and colorectal cancer, indicating its involvement in cytokine-mediated immune responses In contrast, in patients treated with anti-PD-1 therapy, high RNF213 expression was associated with a prolonged median OS of 27.1 months, compared to 15.51 months in the low expression group (P = 0.0052, FDR = 50%) (Fig. [102]8B), indicating that increased RNF213 expression may enhance the efficacy of anti-PD-1 therapy. However, in patients receiving anti-PD-L1 therapy, high RNF213 expression was linked to a shorter median OS of 9.56 months, compared to 12.85 months in the low expression group. This difference, though indicative, was not statistically significant (P = 0.1139, FDR = 100%) (Fig. [103]8C), suggesting that the role of RNF213 in this context might be limited or dependent on other factors. Interestingly, in patients undergoing anti-CTLA-4 therapy, elevated RNF213 expression was associated with a significantly better median OS of 39.47 months, compared to 20.93 months in the low expression group (P = 0.0283, FDR > 50%) (Fig. [104]8D). Moreover, in patients receiving a combination of anti-PD-1 and anti-CTLA-4 therapies, high RNF213 expression was correlated with a notably longer OS, yielding a highly significant P-value of 1.2e-5 (FDR = 1%) (Fig. [105]8E). These findings suggest that RNF213 could serve as a potential biomarker for predicting immunotherapy response, with its effects varying depending on the specific type of immunotherapy administered. Differential expression of RNF213 in response to ICB and cytokine treatment RNF213 expression exhibited significant changes in response to ICB therapy across multiple tumor models. In melanoma, RNF213 expression was significantly elevated in responders compared to baseline in the B16_GSE149825_antiCTLA4&antiPD1 model (FDR ≤ 0.001), suggesting its role in enhancing anti-tumor immunity. Similar trends were observed in colorectal cancer (CT26_GSE139475_antiPD1, FDR ≤ 0.01) and head and neck squamous cell carcinoma (MOC22_RU31562203_antiPD1, FDR ≤ 0.01). In breast cancer models, RNF213 expression was significantly upregulated in responders in both T11_GSE124821_Apobec_day3 and day7 models (FDR ≤ 0.01 and FDR ≤ 0.001, respectively). Interestingly, in gastric adenocarcinoma (YTN16_GSE146027_day14_antiCTLA4), baseline RNF213 expression was higher than in responders (FDR ≤ 0.001), suggesting a context-dependent role for RNF213 (Fig. [106]8F). Overall, RNF213 expression was elevated in most tumor models among responders, indicating its potential involvement in mediating ICB treatment response. In vitro, RNF213 expression was significantly upregulated following cytokine treatment across multiple cancer cell lines. IFNβ treatment induced notable increases in RNF213 expression in breast cancer (4T1RTM28723893, FDR ≤ 0.001), melanoma (B16GSE110708, FDR ≤ 0.001), and colorectal cancer cell lines (CT26RTM28723893, FDR ≤ 0.01). Similarly, IFNγ treatment significantly upregulated RNF213 in breast cancer (4T1RTM28723893, FDR ≤ 0.01) and melanoma cell lines (B16GSE149824, FDR ≤ 0.01). TNFα treatment also led to significant RNF213 upregulation in melanoma (B16RTM28723893, FDR ≤ 0.01) and colorectal cancer cell lines (CT26RTM28723893, FDR ≤ 0.05) (Fig. [107]8G). Across all cytokine-treated samples, RNF213 expression consistently exceeded baseline levels, suggesting its involvement in cytokine-mediated immune responses. Discussion This study provides a comprehensive pan-cancer analysis of RNF213, revealing its diverse roles in tumorigenesis, immune regulation, and the tumor microenvironment. Previous studies have demonstrated that copy number variations (CNVs) in oncogenes such as MYC and TP53 are critical drivers of tumor progression, highlighting the importance of CNVs in cancer biology [[108]26, [109]27]. In our analysis, we observed that CNVs, particularly amplifications, were positively correlated with RNF213 mRNA expression, suggesting that CNVs may serve as a regulatory mechanism driving its overexpression in certain cancers. However, the independent prognostic or predictive value of RNF213 CNV status compared to mRNA expression alone was not directly assessed in this study. Future analyses incorporating patient survival and treatment response data stratified by CNV status are warranted to clarify the relative clinical utility of RNF213 genomic alterations versus expression levels. RNF213 exhibits cancer-type-specific expression patterns, with significant upregulation in glioblastoma and endometrial carcinoma, and downregulation in lung adenocarcinoma and prostate adenocarcinoma. In some cancers, such as colorectal adenocarcinoma and ovarian serous cystadenocarcinoma, RNF213 expression showed no significant differences compared to normal tissues, suggesting its role may be limited or context-dependent in these tumor types. These findings suggest that RNF213 may contribute to tumor progression through genomic alterations, although the precise functional consequences require further investigation. Angiogenesis is a hallmark of cancer, and dysregulated vascular remodeling is a key process in tumor progression [[110]28, [111]29]. RNF213 has been shown to regulate endothelial cell function and vascular remodeling in Moyamoya disease and Vasospastic angina, indicating its potential role in angiogenesis [[112]30, [113]31]. In our study, RNF213 was found to predominantly localize to the ER and microtubules, implicating it in ER-associated processes such as protein folding, stress responses, and lipid metabolism, as well as microtubule-related functions like intracellular transport and cytoskeletal organization. Although reports on RNF213 and lipid droplets are more numerous, there have also been previous studies linking RNF213 to the ER, including its role in modulating ER stress via SEL1L upregulation [[114]19]. Regarding cytoskeletal organization, RNF213’s interactions with cytoskeletal components have been highlighted in Moyamoya disease research [[115]32]. These findings align with its potential involvement in tumor angiogenesis and cellular stress responses, processes frequently dysregulated in cancer. RNF213’s role in vascular remodeling may further suggest its involvement in modulating tumor vascularization, which warrants further exploration. The dual roles of genes in cancer biology are well-documented, with examples such as TP53 and TGF-β, which can act as tumor suppressors or oncogenes depending on the cellular environment and tumor microenvironment [[116]33, [117]34]. Similarly, our analysis revealed that RNF213 exhibits context-dependent associations with tumor progression and patient outcomes. For instance, higher RNF213 expression correlated with early tumor stages in pancreatic adenocarcinoma, ovarian cancer, and skin cutaneous melanoma, suggesting a potential tumor-suppressive role. Conversely, in the pan-kidney cohort, RNF213 expression increased with tumor progression, indicating a possible oncogenic role. Survival analysis further highlighted RNF213’s dual role in cancer prognosis. High RNF213 expression was associated with poor overall survival (OS) in acute myeloid leukemia, low-grade glioma, and uveal melanoma, while it correlated with improved OS in sarcoma and skin cutaneous melanoma. Additionally, high RNF213 expression was linked to reduced disease-free survival (DFS) in low-grade glioma and uveal melanoma. These findings underscore the complexity of RNF213’s prognostic value, which varies significantly across tumor types and contexts. Immune-related genes such as PD-L1 and CTLA-4 are critical modulators of immune cell infiltration and immune evasion in the tumor microenvironment [[118]35–[119]37]. Consistent with this, our analysis revealed that RNF213 is closely associated with immune regulation and the tumor microenvironment. RNF213 expression was positively correlated with immunoregulatory genes across key immune pathways, including chemokines, receptors, MHC molecules, immunoinhibitors, and immunostimulators. Furthermore, RNF213 showed significant associations with both inhibitory and stimulatory immune checkpoints, indicating its involvement in immune evasion mechanisms and its potential as a target for immunotherapy. RNF213 expression was also significantly correlated with immune infiltration scores in 30 cancer types, particularly in glioblastoma, lung adenocarcinoma, and breast cancer, where increased RNF213 expression may enhance immune cell presence within tumors. Specific immune cell types, including B cells, CD4 + and CD8 + T cells, neutrophils, macrophages, and dendritic cells, were strongly associated with RNF213 expression, further supporting its role in shaping the tumor immune landscape. Given these associations, RNF213 expression may reflect or contribute to the immune “hot” tumor phenotype characterized by high immune infiltration, which is generally more responsive to immunotherapies. Conversely, low RNF213 expression could be indicative of “cold” tumors with poor immune cell infiltration and limited immunogenicity. Thus, RNF213 has potential utility both as a biomarker to predict immune responsiveness and, conceivably, as a modulator to convert “cold” tumors into “hot” ones, enhancing immunotherapy efficacy. However, the mechanistic basis of such effects remains to be elucidated. Despite the robust associations observed, the mechanisms by which RNF213 modulates immune responses and contributes to immune evasion or therapy resistance remain poorly understood. It is currently unknown whether RNF213 directly regulates interferon signaling pathways or antigen presentation processes. Given RNF213’s role as an E3 ubiquitin ligase, it may modulate immune signaling indirectly through ubiquitination of key immune regulators. We propose that future mechanistic studies focus on dissecting RNF213’s substrates and downstream pathways in immune cells and tumor microenvironment contexts to clarify its immunomodulatory functions. Immune checkpoint inhibitors have shown variable efficacy depending on the expression of immune-related genes and the tumor immune microenvironment [[120]38–[121]40]. In line with this, our findings suggest that RNF213 plays a significant and context-dependent role in modulating immune therapy outcomes, highlighting its potential as a predictive biomarker in cancer immunotherapy. High RNF213 expression was associated with poorer OS in patients not receiving immune checkpoint blockade (ICB) therapy, suggesting its involvement in promoting tumor progression or immune evasion under untreated conditions. However, it is important to note that the prognostic impact of RNF213 is tumor-type-dependent. While a negative correlation between high RNF213 expression and prognosis is observed in several cancers under untreated conditions, this is not universal across all tumor types targeted by immune checkpoint therapies. For instance, in non-small cell lung cancer (NSCLC), where immune checkpoint inhibitors are commonly used, high RNF213 expression has been reported to correlate positively with immune cell infiltration and favorable prognosis, indicating a role in antitumor immune activation [[122]18]. This highlights the complexity of RNF213’s role in the tumor immune microenvironment and underscores the necessity for stratified analyses by cancer type to accurately interpret its prognostic value. Conversely, high RNF213 expression correlated with improved OS in patients treated with anti-PD-1 or anti-CTLA-4 therapies, indicating its potential role in enhancing immune activation and amplifying anti-tumor responses. Notably, the significant survival advantage observed in patients with high RNF213 expression receiving combined anti-PD-1 and anti-CTLA-4 therapy suggests a synergistic effect, wherein RNF213 may enhance the combined efficacy of these therapies. However, the lack of significant survival benefit in the anti-PD-L1 cohort underscores the complexity of RNF213’s interactions with immune signaling pathways, which may vary depending on the specific checkpoint targeted. Compared to PD-1, PD-L1 is a tumor-intrinsic factor and may be more directly influenced by tumor-specific changes in RNF213. Given that RNF213 is also expressed in immune cells, both tumor-intrinsic and germline alterations could impact patient outcomes. Importantly, our study could not differentiate between tumor-specific and blood-derived (germline) alterations, which represents a limitation. Notably, Liu ZX et al. reported that RNF213 exhibited one of the highest incidences (> 10%) of private germline alterations, including insertions and deletions, in a hereditary diffuse gastric cancer (HDGC) cohort [[123]41]. This finding suggests that germline variants of RNF213 may contribute to cancer susceptibility and patient prognosis, underscoring the need for future studies to dissect the relative contributions of tumor-specific versus germline RNF213 alterations in cancer biology and therapy response. Furthermore, it is plausible that high RNF213 expression contributes to an immunoinhibitory tumor microenvironment, which may partly explain the observed poorer prognosis in patients not receiving immune checkpoint blockade. The efficacy of PD-1 blockade in improving outcomes in such contexts aligns with this notion, as PD-1 inhibitors may counteract RNF213-mediated immune suppression. Additionally, recent studies have demonstrated that RNF213 promotes regulatory T cell (Treg) differentiation by facilitating K63-linked ubiquitination and nuclear translocation of FOXO1, a key transcription factor in Treg biology [[124]42]. This mechanism suggests a potential pathway through which tumor-intrinsic RNF213 alterations could modulate immune responses and contribute to immune evasion. However, linking tumor-specific RNF213 alterations directly to immune modulation remains an important challenge and warrants further mechanistic investigations. Limitations While our study provides valuable insights into the expression and mutation patterns of RNF213 across various cancers, several limitations should be acknowledged. First, the study relies on publicly available datasets, which may introduce biases related to sample heterogeneity and data quality. Second, the lack of experimental validation limits the ability to draw definitive conclusions about RNF213’s functional roles in specific cancers. Third, the uniform application of a 50% expression threshold to divide patients into high and low RNF213 expression groups across all cancer types may not be optimal, as it overlooks potential non-linear (e.g., U-shaped or J-shaped) associations between RNF213 expression and clinical outcomes. Due to data constraints, cancer type-specific threshold optimization was not feasible in this study. This limitation may have led to inaccurate prognostic evaluations in certain tumor types and should be considered when interpreting the results. Fourth, our analyses could not distinguish between tumor-intrinsic and germline or blood-derived RNF213 alterations, which may differentially influence tumor biology and immune responses. This represents an important limitation and highlights the need for future research integrating paired tumor-normal sequencing and functional assays to clarify these effects. Clinically, while our study establishes RNF213 as a potential biomarker, its direct application remains to be defined. Future studies should focus on experimental validation of these findings and explore the molecular mechanisms underlying RNF213’s diverse roles in tumorigenesis and immune regulation. Integrating multi-omics approaches could provide a more comprehensive understanding of RNF213’s role in cancer biology and its potential as a therapeutic target. Addressing these limitations in future studies will enhance our understanding of RNF213’s role in cancer and its potential as a biomarker and therapeutic target. Conclusion In summary, this study provides a comprehensive pan-cancer analysis of RNF213, highlighting its diverse and context-dependent roles in tumorigenesis, immune regulation, and the tumor microenvironment. RNF213 exhibits cancer-type-specific expression and genomic alterations, with its dysregulation linked to both tumor-suppressive and oncogenic functions depending on the cancer type and clinical context. Furthermore, RNF213 is closely associated with immune pathways, immune cell infiltration, and immune checkpoint regulation, underscoring its potential as a key modulator of tumor immunity. Importantly, RNF213 shows promise as a predictive biomarker for cancer immunotherapy, particularly in the context of immune checkpoint blockade therapies. While this study provides novel insights into RNF213’s functional and clinical significance, further experimental validation and mechanistic studies are required to fully elucidate its roles in cancer biology and to explore its potential as a therapeutic target. These findings lay the groundwork for future research aimed at leveraging RNF213 for improved cancer diagnosis, prognosis, and treatment strategies. Electronic supplementary material Below is the link to the electronic supplementary material. [125]Supplementary Material 1^ (29.2KB, xlsx) [126]Supplementary Material 2^ (11.4KB, xlsx) Abbreviations ACC Adrenocortical carcinoma BLCA Bladder urothelial carcinoma BRCA Breast invasive carcinoma CESC Cervical squamous cell carcinoma and endocervical adenocarcinoma CHOL Cholangiocarcinoma COAD Colon adenocarcinoma DLBC Lymphoid neoplasm diffuse large B-cell lymphoma ESCA Esophageal carcinoma GBM Glioblastoma multiforme HNSC Head and neck squamous cell carcinoma KICH Kidney chromophobe KIRC Kidney renal clear cell carcinoma KIRP Kidney renal papillary cell carcinoma LAML Acute myeloid leukemia LGG Brain lower grade glioma LIHC Liver hepatocellular carcinoma LUAD Lung adenocarcinoma LUSC Lung squamous cell carcinoma MESO Mesothelioma OV Ovarian serous cystadenocarcinoma PAAD Pancreatic adenocarcinoma PCPG Pheochromocytoma and paraganglioma PRAD Prostate adenocarcinoma READ Rectum adenocarcinoma SARC Sarcoma STAD Stomach adenocarcinoma SKCM Skin cutaneous melanoma TGCT Testicular germ cell tumors THCA Thyroid carcinoma THYM Thymoma UCEC Uterine corpus endometrial carcinoma UCS Uterine carcinosarcoma UVM Uveal melanoma Author contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by J.P.W., Z.K.L. and M.J.L. The first draft of the manuscript was written by J.P.W. C.T.Y.and C.M.Z. commented on previous versions of the manuscript. supervision was managed by C.T.Y.and C.M.Z. All authors read and approved the final manuscript. Funding This work was supported by the Natural Science Foundation of Zhejiang Province (LQ22H160063); the Zhejiang Medical and Health Science and Technology Project (2022KY064); the Project of Administration of Traditional Chinese Medicine of Zhejiang Province of China (2021ZQ011); and the Basic Scientific Research Funds of the Department of Education of Zhejiang Province (KYQN202111). Data availability All data supporting the findings of this study are available within the paper and its Supplementary Information. Declarations Competing interests The authors declare no competing interests. Footnotes Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Contributor Information Chuanming Zheng, Email: mingdoc@163.com. Changtian Yin, Email: yin454593539@163.com. References