Pipersentan efficaciously antagonized the effects of ET-1 on pulmonary artery smooth muscle cell proliferation, migration and calcium mobilization and effectively improved right ventricular hypertrophy and pulmonary arterial pressure in both monocrotaline- and hypoxia-induced pulmonary hypertension (PH) rat models. The gene discussed is EDN1; the disease is Right ventricular hypertrophy.