IL2 and type 1 diabetes mellitus: Natural Killer (NK) cells also require higher concentrations of IL-2 to be activated since this subset primarily expresses the intermediate affinity IL-2 receptor that is composed of dimers of the β and γ chains.12 The higher sensitivity of Tregs for IL-2 opens a therapeutic window where ultra-low doses (ULD) of IL-2 therapy can be used to enhance Treg responses in patients with T1D without increasing Teff or NK cells.