We and others have shown that T1D progression is NOD mice is associated with a decrease in numbers and function of Treg cells in the inflamed islets and defects in IL-2 production by effector T cells seem largely responsible (Sgouroudis et al., 2008; Tang et al., 2008; Tritt et al., 2008; Kornete et al., 2012). This evidence concerns the gene IL2 and type 1 diabetes mellitus.