At this level, it determines vasoconstriction and pulmonary artery smooth muscle cell proliferation (elevated levels of ET-1 were identified in the plasma and endothelium of remodeled pulmonary microvessels of patients with pulmonary arterial hypertension, as well as chronic thromboembolic pulmonary hypertension) [34,35,36]. Here, EDN1 is linked to chronic thromboembolic pulmonary hypertension.