Treatment with mInsA2-10DQ4 significantly suppressed the development of T1D in NOD.β2mnull.HHD mice via inducing mInsA2-10 autoreactive CD8+ T cell tolerance and preventing the subsequent infiltration of CD4+ T and CD8+ T cells as well as inflammatory responses in the pancreas in NOD.β2mnull.HHD mice. This evidence concerns the gene CD8A and type 1 diabetes mellitus.