HIF1A and cancer: Although the Warburg effect shows that most cancer cells preferentially use aerobic glycolysis to provide ATP and key metabolites [78], this effect is maintained by hypoxia-inducible factor-1α (HIF-1α) [79] which requires NAD+/NADH balance produced by complex I. This balance is also required for nucleic acid synthesis for DNA replication and cancer cell proliferation further highlighting the key role of complex I in these processes.