Indeed, administration of low dose (LD) IL-2 has been used as a therapeutic strategy to preferentially induce Treg expansion, without stimulating effector T cells, in a number of immune disorders including alopecia areata1, chronic graft-versus-host disease2, hepatitis-induced vasculitis3, systemic lupus erythematosus4, and type 1 diabetes (T1D)5,6, in order to limit harmful immune responses. This evidence concerns the gene IL2 and type 1 diabetes mellitus.