From the annotations related to immune responses, it is plausible to suspect MARCH3 (involved in regulation of the endosomal transport pathway), MAST3 (highly expressed in antigen-presenting cells and in lymphocytes) and STAB2 (involved in lymphocyte homing, cell adhesion, and receptor scavenging) as candidate for the causal genes for susceptibility to mastitis. Here, MAST3 is linked to mastitis.