Two authors (GT and SG) conducted electronic database searches in PubMed, the Cochrane Library, and Excerpta Medica Database (EMBASE) for relevant studies published from the inception of the databases to March 15th, 2023, using the following combination of keywords or key terms: "Renin-angiotensin-system," "ACE inhibitors," "Angiotensin receptor blockers," and "advanced chronic kidney disease." These key terms were combined using Boolean algebra operators (and, or). The gene discussed is REN; the disease is chronic kidney disease.