HIF1A and cancer: Lactate (lac−) accumulation (up to 40 mM in heterogeneously distributed subvolumes of human cancers) (5) is a secondary consequence of hypoxia upon HIF-1α-induced reprogramming of metabolic pathways [e.g., upregulation of the glycolytic enzyme lactate dehydrogenase A (LDH-A) and accelerated glycolysis, “Warburg effect”].