To determine the causative effect of caspase-1 in HIV-1-associated atherosclerosis, we compared the development of atherosclerosis in caspase-1-sufficient vs. -deficient mice carrying the HIV transgene with an atherogenic background (Tg26+/−/ApoE−/−/Casp-1+/+ vs. Tg26+/−/ApoE−/−/Casp-1−/−). The gene discussed is CASP1; the disease is atherosclerosis.