The Bluestone group applied a low-dose regiment of IL-2 to NOD mice, and obtained a strong delay or complete abrogation of diabetes (Tang et al., 2008): concomitantly, they reported that Treg cells harvested from the pancreatic islet were more abundant (27% instead of 7% among CD4+ T cells) and expressed higher levels of IL-2Rα (20-fold higher). This evidence concerns the gene IL2RA and diabetes mellitus.