EPAS1 and infection: The overexpression of HIF-2α mediated by infection with Ad-Hif-2α inhibited the AA/β-Gp-mediated osteoblast differentiation of mouse calvarial preosteoblasts, as determined by alkaline phosphatase and alizarin red S staining (Supplementary Fig. 3c), whereas increased osteoblast differentiation from Hif-2α+/− calvarial preosteoblasts was observed (Fig. 2c).