DNA methylation of some immune-related genes has been associated with mastitis, such as CXCR1 and CDH13. CXCR1 gene polymorphism was shown to impact milk production and sensitivity to mastitis, and was selected as a candidate marker for improving bovine resistance to mastitis (Verbeke et al., 2015; Pokorska et al., 2016; Siebert et al., 2017). Here, CDH13 is linked to mastitis.