A region on Chr4 included three GTPase genes (GIMAP7, GIMAP4, and GIMAP8), IMAP family members that have been related to the primary immunodeficiency pathway and were shown to play a major role in feed utilization and the metabolism of lipids, sugars, and proteins in Jersey cattle (Salleh et al., 2017). Here, GIMAP8 is linked to immunodeficiency disease.