That three of the HLA genes (DRB1, DRB5, and C) were found to have bimodal distributions - as well as ERAP2 which plays a final role in producing HLA peptides [34], is of great interest, and we are currently further investigating the role of these genes in relation to diabetes and various metabolic phenotypes in the Pima population. The gene discussed is HLA-DRB5; the disease is diabetes mellitus.