Significant progress has also been made on the mechanism of HIF2α in the pathogenesis of PAH and it appears that HIF2α causes PH by inducing endothelial-to-mesenchymal transition (Endo-MT), a phenomenon of endothelial cells transforming into fibroblast phenotype, which exacerbates pulmonary vascular lesions (Tang et al., 2018). Here, EPAS1 is linked to pulmonary arterial hypertension.