Since insulin has been considered as an only essential autoantigen to initiate spontaneous T1D and the elimination of insulin-reactive T cells can block epitopes expansion and subsequent destruction of β cells by other autoreactive T cells in NOD mice, we questioned whether the treatment of mInsA2-10DQ4 prevented the infiltration of CD4+ and CD8+ T cells and inflammatory responses in the pancreas of NOD.β2mnull.HHD mice. This evidence concerns the gene CD4 and type 1 diabetes mellitus.