Renin–angiotensin system (RAS) inhibitors, comprising angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs), are first-line therapy for essential hypertension and heart failure, and also used as interventions of secondary prevention in coronary heart disease, diabetes mellitus, and diabetic nephropathy.1, 2, 3, 4. This evidence concerns the gene ACE and essential hypertension.