The enrichment analysis of the KEGG signaling pathway for those DEGs found only in water buffalo showed that they are mainly involved in metabolic pathways, T cell receptor signaling pathways, histidine metabolism, vascular smooth muscle contraction, base excision repair, primary immunodeficiency, leukocyte transendothelial migration, natural killer cell-mediated cytotoxicity, the neurotrophin signaling pathway, the insulin signaling pathway, the Wnt signaling pathway, antigen processing and presentation (S9 Table). This evidence concerns the gene BDNF and inborn error of immunity.