In mice, PH induced by chronic hypoxia or pulmonary arterial hypertension (PAH) caused by Tie2-mediated Phd2 (Egln1, official gene symbol) disruption can be prevented by global or cell-specific deletion or heterozygous knockout of Hif2α (Epas1, official gene symbol; 3–7). Here, EGLN1 is linked to pulmonary arterial hypertension.