Here are the answers to your questions:

1. What tool was used for pathway enrichment analysis?
The tools used for pathway enrichment analysis were not explicitly described as "pathway enrichment analysis" tools, but rather as tools for functional category analysis (e.g., "functional categories", "GO analysis"). However, based on the context, it appears that the authors used the Gene Ontology (GO) database and possibly other databases to analyze functional categories. Additionally, the authors mentioned using the STRING database to identify protein-protein interactions.

2. Was a tool version number provided?
Not described.

3. What gene set library was queried (eg: GO, KEGG, Reactome or other)?
The Gene Ontology (GO) database was explicitly mentioned as being used for functional category analysis. Other databases, such as the STRING database, were also used to identify protein-protein interactions.

4. Was a background gene list defined for pathway enrichment analysis?
Not described.

5. What statistical test was used for enrichment analysis?
Not described.

6. Was false discovery rate correction used to control the number of false positives in the pathway enrichment analysis?
Not described.

Let me know if you'd like me to help with anything else!