EPAS1 and hemangioblastoma: We established that propranolol decreased HIF-dependent transcription in 9XHRE HeLa cells under hypoxia and in hemangioblastoma cells constitutively expressing HIF, as shown in Fig. 7a, the amounts of HIF1α and HIF2α protein under hypoxic conditions in HeLa cells were decreased by propranolol treatment.