The use of these medications in CKD has been extensively evaluated, and based on the collaborative study group trial and several others, the use of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) in patients with CKD with proteinuria is now a level-one recommendation by the Kidney Disease Outcomes Quality Initiative (KDOQI) [93]. This evidence concerns the gene ACE and chronic kidney disease.