IL2 and type 1 diabetes mellitus: Additionally, the risk and benefit of cellular therapies using in vitro expanded Treg cells or pharmacological modulators of Treg cell function like rapamycin or IL-2 is comparatively discussed by Perdigoto et al. Complementary, Pham et al. provide an updated view on the use of low dose IL-2 in combination with tissue-specific antigens as a therapeutic approach to expand and activate antigen-specific Treg cells in patients with type I diabetes (Pham et al.), an approach that will be currently used by different groups for treatment of T cell-mediated autoimmunity.