REN and cyclic hematopoiesis: A large number of CH treatment drugs have been developed based on different principles—for example, β-blockers involved in blocking sympathetic tone, thiazidic or thiazid diuretics that produce natriuresis [4,5], antirenins that act as calcium channel blockers, and renin–angiotensin–aldosterone system (RAAS) blockers that act on the renin angiotensin aldosterone axis, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin type 1 receptor blockers (Ang) II (ATR1).