To determine the role of the IFIH1 risk variant in the immune cell compartments during diabetes pathogenesis in vivo, we generated a mouse strain with the Ifih1 risk allele that precisely mimicked the haplotype of two human T1D risk variants, rs3747517 (IFIH1H843R) and rs1990760 (IFIH1A946T), that were previously shown to be significantly associated with T1D (21). The gene discussed is IFIH1; the disease is type 1 diabetes mellitus.