Moreover, most of the candidate genes for mastitis resistance identified in the present study were previously reported to control mastitis resistance in dairy cattle, including CTLA4 [40], IDH1, OSMR, C6, C7 and C9, mitogen-responsive phosphoprotein, homolog 2 (DAB2), caspase recruitment domain family, member 6 (CARD6) [41, 42], and prostaglandin E receptor 4 (PTGER4) [43, 44]. This evidence concerns the gene PTGER4 and mastitis.