Hypoxia is intricately linked to pluripotency as it promotes stem cell maintenance and self-renewal in both embryonic stem cells and CSCs,38 in part, through modulating hypoxia-inducible factor (HIF) function.39 For example, glioma stem cells are typically found in the vicinity of necrotic regions that are hypoxic.40 Glioma stem cells have increased ability to stimulate angiogenesis through VEGF upregulation41 and inhibition of HIFs could reduce CSC survival, self-renewal and proliferation.40 We reason that hypoxia functions to maintain CSC niches. This evidence concerns the gene VEGFA and glioma.