In the clinic, low-dose IL-2 therapy has been shown to selectively expand FOXP3 Tregs and used successfully to treat chronic GVHD (82), hepatitis C virus–induced vasculitis (83), systemic lupus erythematosus (SLE) (84), and type 1 diabetes (85, 86). The gene discussed is FOXP3; the disease is systemic lupus erythematosus.