Angiotensin-converting enzyme (ACE) inhibitors are a group of therapeutic agents widely used and listed as first-line agents in the treatment of hypertension, congestive heart failure, myocardial infarction, and left ventricular systolic dysfunction; they are either used alone or in combination with other classes of drugs with different mechanisms of action [1,2,3,4]. The gene discussed is ACE; the disease is hypertensive disorder.