As IL-2/IL-2R might be the activation pathway relative to T1D (47), the safe and effective dose range of IL-2 for T1D therapy was investigated, showing that appropriate dosage of IL-2 facilitated β-cells persistence (47–49).What’s more, a recent clinical trial verified previous conclusion that IL-2 is a major role both in the development of T1D and the function of Tregs (50). This evidence concerns the gene IL2 and type 1 diabetes mellitus.