found that CTLA-4 had a protective effect on Ang II-induced AAA formation in mice, which was related to the decrease in the number of efficent CD4+ T cells and the down-regulated expression of CD80 and CD86 co-stimulatory molecules of CTLA-4 ligand on CD11c+ DCs in lymphoid tissue (56). The gene discussed is CD4; the disease is triple-A syndrome.