Hif-2α deletion affects HIF target gene expression in lung endothelial cells. (A-B) Hypoxic induction of HIF target gene expression in ECs isolated from KO mice (A) and from ECs with HIF-2α acute deletion (B) exposed to 0.5% O₂ for 16 hours. The relative ratio of hypoxic to normoxic gene expression (fold hypoxic induction) is shown for control and KO ECs. See “Endothelial HIF-2α deletion disrupts vessel integrity and promotes pulmonary hypertension” and “Hypoxic induction of angiogenic genes is impaired in HIF-2α–deficient ECs” for gene names (n = 6; *P < .05; **P < .01). (C) Model of HIF-2α function in murine ECs in response to hypoxia, reflecting unique and shared transcriptional targets of HIF-1α and HIF-2α.