ACE and Hypertension: In addition to GRK4, gene polymorphisms related to the renin-angiotensin-aldosterone system (RAAS), such as angiotensin converting enzyme (ACE), angiotensinogen (AGT), angiotensin II type 1 receptor (AGTR1), and aldosterone synthase (CYP11B2) [5], have been reported to be associated with hypertension.