Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of target genes

The GO resource (http://geneontology.org/) is an online database that provides biological information like the function of genes and gene products [38,39]. The GO resource was used to implement functional enrichment analysis of significant target genes with P<0.05 [40]. The KEGG pathway enrichment analysis was performed using KEGG Orthology Based Annotation System (KOBAS) (version 3.0) (http://kobas.cbi.pku.edu.cn/anno_iden.php). KOBAS is a web server that can be used to identify significantly enriched pathways by mapping to genes with known annotations [41–43]. P<0.05 was considered as statistically significant.