The importance of IL-2R signaling in thymic Treg differentiation is clearly demonstrated by the fact that the lethal autoimmunity in mice lacking Il2rb is due to a failure to generate thymic Tregs, and this phenotype is completely restored by adoptive transfer of small numbers of wild-type Tregs.41 Moreover, retroviral transduction of Il2rb−/− bone marrow with wild-type Il2rb, or a mutant construct capable of activating only STAT5 via Tyr-510, restored thymic Treg generation in bone marrow of chimeric mice. This evidence concerns the gene IL2RB and Autoimmunity.