FOXP3 and Autoimmunity: Strikingly, dysfunctional, instable or insufficient Foxp3 expression can also trigger autoimmunity (15, 208–212): Upon loss of Foxp3, Tregs lose their immunosuppressive capacity adapting phenotype and functionality of Th cells (Th1, Th2, Th17), such as production of IFNγ and IL-17 (Figure 1) (213–215).