TGFB1 and type 1 diabetes mellitus: Likewise, there is a single report of Breg protection against NOD-T1D, the mechanism of which involves TGF-β-production and FasL-mediated apoptosis of auto-reactive T cells [35], but perhaps reflecting the paucity of research in this area, B cell depletion studies in NOD mice and T1D patients suggest that Bregs play a very minor, if any, role in preventing T1D [35].