Pathway enrichment analysis of DEGs
DAVID (The Database for Annotation, Visualization and Integrated Discovery), as a comprehensive set of functional annotation tools, is used for systematic and integrative analysis of large gene lists (Huang et al., 2008). The Kyoto Encyclopedia of Genes and Genomes (KEGG) (Kanehisa, 2002) pathway enrichment analysis for the identified DEGs was performed by DAVID Fisher test with the thresholds of p value 2 ( Fisher, 1948).