In consideration of our findings of the protective role of CTLA-4 in AAA formation, it will be of great interest to test the hypothesis that an immunomodulatory approach such as costimulatory blockade by CTLA-4-Ig would be effective for preventing the development of atherosclerotic cardiovascular disease and AAA in patients with rheumatoid arthritis. The gene discussed is CTLA4; the disease is triple-A syndrome.