It is encouraging for the future use of inducible models of type 1 diabetes that the immune infiltrate in the pancreatic islets is very similar in the spontaneous-onset DR3DQ2×RIP-B7.1 model and the induced DR4×RIP-B7.1 model and that the diversity of immune cells infiltrating is reminiscent of human type 1 diabetes and other major preclinical models such as the non-obese diabetic (NOD) mouse [15]. This evidence concerns the gene CD80 and type 1 diabetes mellitus.