It is with great interest to see whether the HIF-2α inhibitor drug Welireg, recently approved for treatment of adult patients with von Hippel–Lindau disease who require therapy for associated renal cell carcinoma, is effective in inhibiting PAH progression and occlusive pulmonary vascular remodeling and improving survival of PAH patients. The gene discussed is EPAS1; the disease is pulmonary arterial hypertension.