The inhibitor dose-dependently decreased ET-1 induced cell constriction in non-PAH HPASMC at 1 uM with a complete abrogation at 10 uM (Fig 6A) while it equivalently affected ET-1 induced cell constriction in PAH HPASMC at a much higher inhibitor concentration, 10 and 25 uM respectively (Fig 6B). The gene discussed is EDN1; the disease is pulmonary arterial hypertension.