Here are the answers to the questions:

1. What tool was used for pathway enrichment analysis?
Not described

2. Was a tool version number provided?
Not described

3. What gene set library was queried (eg: GO, KEGG, Reactome or other)?
GO (mentioned in the Discussion section as " Gene Expression Omnibus (GEO) repository")

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

Note: The article does not provide detailed information on how the pathway enrichment analysis was conducted, so most of the answers are "Not described".