BCL2 and neoplasm: Hypoxia in solid primary tumor tissues or the metastatic microenvironment, promotes stabilization and activation of hypoxia-inducible factor-1a (HIF-1a), which participates in activating erythropoiesis, glycolysis, angiogenesis, cell growth, metastasis, and p53, as well as in regulating transcription of ABC transporter genes and Bcl-2 [160].