Overactivity of the renin–angiotensin–aldosterone system (RAAS)is the most important mechanism of myocardial hypertrophy as it can promotevasoconstriction, cardiac ischemia, myocardial apoptosis, and fibrosis, which arefundamental to ventricular tachyarrhythmias [28]. The gene discussed is REN; the disease is cardiac hypertrophy.