While Tregs are primarily known for their stable expression of FOXP3 and suppressive activity to prevent inflammation, deficiency of FOXP3 in both humans and mice results in the depletion of Tregs and leads to the development of severe systemic inflammatory diseases including immune dysregulation polyendocrinopathy enteropathy X‐linked (IPEX) syndrome,16, 17, 18 graft‐versus‐host disease (GVHD),19, 20, 21 solid organ transplantation,22, 23 type 1 diabetes (T1D),24, 25 systemic lupus erythematosus (SLE),26, 27 and multiple sclerosis (MS).28, 29. The gene discussed is FOXP3; the disease is type 1 diabetes mellitus.