The gene encoding angiotensin II type 1 receptor (AT1) is mapped on 3q21-q25 region, and a polymorphism, A1166C, is located at 3'untranslated region (UTR). A1166C is associated with increased risk for hypertension, aortic stiffness, left ventricular hypertrophy and diabetic nephropathy, and synergistically increases the risk for ischemic heart disease with DD polymorphism of angiotensin converting enzyme gene. However, these results were still in controversy. On the other hand, the gene encoding angiotensin II type 2 receptor (AT2) gene is mapped on Xq22-q23 region, and a polymorphism, C3123A, is identified at 3'UTR of AT2 gene. However, any significant association with C3123A has not been obtained in case control studies yet.