The potentiation of TCR-stimulated IL-2 production that results from Gβγ inhibition suggests that Gβγ could be a useful drug target for treating autoimmune diseases, as low dose IL-2 therapy has been shown to effectively suppress immune responses in chronic graft-versus-host disease [8] and hepatitis C virus-induced vasculitis [9]. Here, IL2 is linked to chronic graft versus host disease.