The results of KEGG pathway analysis (Figs 3A, 3B and 3C) suggested that the DEGs were mainly related to several types of cancers, virus infection, life cycle of cells and signaling pathways such as PI3K-Akt signaling pathway, MAPK signaling pathway, Insulin signaling pathway, AMPK signaling pathway, Neurotrophin signaling pathway and AGE-RAGE signaling pathway. This evidence concerns the gene BDNF and viral infectious disease.