2.4 Functional enrichment analysis
The R package “clusterProfiler” 9 was applied for the enrichment of Gene Ontology (GO) biological process and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Enrichment significance was estimated using the default setting and 1000 permutations. Benjamini-Hochberg adjusted P-values less than 0.05 was considered as statistically significant. The KEGG pathway overview was implemented by the R package “pathview” 10.