Another factor that contributes to the development of age-induced hypertension is endothelial dysfunction, which is a condition associated with an imbalance in the production of vasodilating agents, such as nitric oxide (NO), and vasoconstrictor agents such as endothelin-1 (ET-1) by the vascular endothelium that results in impaired vasodilation [33]. The gene discussed is EDN1; the disease is endothelial dysfunction.