 The renin-angiotensin-aldosterone system in chronic renal failure: The importance of the RAAS in CRF is illustrated by the efficacy of ACE inhibitors in retarding the progression of diabetic and non-diabetic renal disease. The significance of ANG II mediated renal damage was shown by the finding that combined treatment with ACE inhibitors and ARBs further slows the progression of non-diabetic renal disease compared with either agent alone. 