HIF1A and cancer: It is now widely accepted that HIF1α and its responsive genes encoding glycolytic enzymes and glucose transporters, among others, are upregulated in cancer cells as the consequence of metabolic shift of glucose metabolism from the more energetic efficient mitochondrial oxidative phosphorylation (OXPHOS) pathway to the less energetic efficient glycolytic pathway, even when oxygen level is adequate (the Warburg effect) (Xie & Simon, 2017).