The function of angiotensin II has evolved from recognition of its vasoconstrictive functions and regulations of fluid balance to its pivotal role in progressive tissue destruction, particularly renal scarring. This review highlights angiotensin's newest role in normal and abnormal organogenesis as well as the impact on renal damage of subtle variations in genes that control angiotensin's actions including angiotensinogen, angiotensin converting enzyme, and its receptors.