HIF1A and glioblastoma: Hypoxia is one of the key characteristics of GBM and glioma cells shift to aerobic glycolysis as a main source of ATP, a phenomenon referred to as the Warburg effect.84 As one of the chief glycolytic enzymes and upregulated by HIF-1α, HK2 is a compelling metabolic target because of its strong presence in gliomas and its role in maintaining high glycolytic rates.