CTLA4 and triple-A syndrome: Notably, we found here that the protective effects of CTLA-4 in AAA were associated with attenuation of the angiotensin II-mediated shift of the Th1/Th2 balance toward a Th1 immune response, as well as suppression of all helper T-cell-mediated immune responses such as Th1, Th2, and Th17 immune responses.