For example, if there is a tendency toward ischemic heart disease (IHD) or if it is already diagnosed, the optimal 3 drugs for uncomplicated HTN will have to include recommended treatments for IHD, such as beta blocker (BB), calcium channel blocker (CCB), and renin-angiotensin-aldosterone (RAAS) blocker [22]. The gene discussed is REN; the disease is coronary artery disorder.