EDN1 and pulmonary arterial hypertension: Since the first therapeutic approach in the 1950s, treatments have evolved and, currently, PAH treatments target three main deregulated pathways: the ET-1 pathway with ET-1 receptor antagonist (Bosentan, Ambrisentan, and Macitentan), the NO pathway with PDE5 inhibitors (Sildenafil and Tadalafil) or guanylate cyclase stimulators (Riociguat) and the prostacyclin pathway with prostacyclin analogs (Epoprostenol and Treprostinil) or prostacyclin receptor agonist (Selexipag) [19].