The ACE–Ang II–AT1-R axis hyperactivation commonly leads to deleterious effects such as vasoconstriction, inflammation, endothelial dysfunction, thrombosis, and the well-established pro-hypertensive profile; the other, ACE2–Ang (1-7)–MasR typically reverts the forementioned effects. The gene discussed is AGTR1; the disease is endothelial dysfunction.