IKZF2 and type 1 diabetes mellitus: We observed that expression of CTLA4 and CD28 (MFI) was higher in Helios− Tregs compared to Helios+ Tregs in both T1D and healthy individuals (P < 0.0001) (Figures 5B, D), suggesting Helios+ and Helios− Tregs are two distinct subpopulations.