To answer your questions based on the provided scientific article:

1. **What tool was used for pathway enrichment analysis?**
   - The DAVID tool was used for functional annotation and pathway enrichment analysis.

2. **Was a tool version number provided?**
   - No, the version number of the DAVID tool is not specified in the article.

3. **What gene set library was queried (e.g., GO, KEGG, Reactome or other)?**
   - The gene set libraries queried were based on Gene Ontology and KEGG pathway databases.

4. **Was a background gene list defined for pathway enrichment analysis?**
   - Yes, the categories of KEGG Pathways served as background databases for the analysis.

5. **What statistical test was used for enrichment analysis?**
   - The specific statistical test used is not described in the article.

6. **Was false discovery rate correction used to control the number of false positives in the pathway enrichment analysis?**
   - No, there is no mention of using a false discovery rate correction in the article.

These details should help summarize the methodology related to pathway enrichment analysis as described in the study.