3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of cholesterol synthesis and statins which are HMG-CoA reductase inhibitors have been increasingly used in patients with hypercholesterolemia and/or at risk of vascular diseases [34]. The gene discussed is HMGCR; the disease is Hypercholesterolemia.