Based on other findings that the Blimp-1 mRNA expression is greater in Tregs than in conventional T cells (Tconvs) and that Blimp-1 critically controls Treg suppressive function in dextran sodium sulfate-treated C57BL/6 mice,13 we explored the immunomodulatory function and underlying mechanisms of Blimp-1 in Tregs in diabetes-prone NOD mice. Here, PRDM1 is linked to diabetes mellitus.