High pulmonary levels of ET-1 in PAH have been recognized for 20 years, and several endothelial receptor antagonist therapies are known to offer clinical benefit [41], [42]; we, therefore, measured the ET-1 levels in the supernatant of the HLMVE cells after they were transfected with BMPR2 mutants. This evidence concerns the gene EDN1 and pulmonary arterial hypertension.