IL2 and systemic lupus erythematosus: Up to date, numerous studies have investigated the role of Treg in mouse models of lupus and in SLE patients and based on these findings it is meanwhile broadly accepted that a disturbance in Treg biology, in particular of the Treg-IL-2 axis, plays a significant role in the pathogenesis of this complex disease (24, 25, 27, 32–38).