Upregulation of GH may cause hypertension, arrhythmias, diabetes mellitus, concentric cardiac hypertrophy, coronary artery disease, chronic heart failure, and stroke4, whereas downregulation of GH is characterized by dyslipidemia, insulin resistance, endothelial dysfunction, vascular atherosclerosis, a decrease in cardiac mass together with a post-exertional impairment of systolic function5. The gene discussed is GH1; the disease is endothelial dysfunction.