REN and chronic kidney disease: Angiotensin inhibition with ACEi and angiotensin receptor blockers, cumulatively known as renin–angiotensin–aldosterone system (RAAS) blockers, used in other albuminuric/proteinuric kidney diseases and CKD,76, –78 have long been used in the treatment of sickle nephropathy; however, hyperkalemia has limited widespread adoption in real-world settings.