HIF1A and neoplasm: To date, >100 putative HIF-1 target genes have been identified.(51–54) They are involved in a wide variety of biological processes including energy metabolism, angiogenesis, erythropoiesis, cell survival, apoptosis, redox, and pH regulation.(53,55) Mouse embryos lacking HIF-1α exhibit multiple morphological defects as early as embryonic day E8.5 and die in utero by E10.5.(56–58) Many malignant cancers contain regions of severe hypoxia, resulting in high levels of HIF-1α that drive tumor progression,(32,35) and inhibition of HIF-1α has been proposed as a potentially powerful approach.(59)