Further mice studies showed that low-dose IL-2 prevented the onset of T1D and preserved beta cell functions in NOD mice by increasing the numbers of Tregs in the pancreas and inducing expression of Treg-associated proteins (e.g., FoxP3, CD25, CTLA-4, ICOS, and GITR) in these cells. This evidence concerns the gene IL2 and type 1 diabetes mellitus.