EPAS1 and breast cancer: To further study whether HIF-2α induces conversion to a stem cell phenotype and resistance of breast cancer cells to PTX by activating the Wnt pathway and increasing c-Myc expression, we first treated HIF-2α overexpressing MCF7 cells with DKK (100 ng/ml), a Wnt pathway inhibitor, and detected changes in Wnt pathway-related proteins by western blot.