PTAFR and infection: The folic acid supplementation also regulated many important genes associated with immune response such as MHC class II antigen (BLA-DQB), TNFRSF1A, CXCL8, CXCL10, PTAFR, CXCR1, CXCR5, and CCL5. Importantly, our previously published study [22] documented the up-regulation of the CXCR1, NFKBIA, SOCS3, Pim-1 proto-oncogene, serine/threonine kinase, dual specificity phosphatase 4, zinc finger CCCH-type containing 12A, and NFKBIA in mammary epithelial cells after infection by S. aureus in vitro, while these genes showed significantly downregulated status in folic acid treated cows.