Most of these studies indicated that the tumor cell content of many mitochondrial enzymes include β-hydroxybutyrate dehydrogenase, malate dehydrogenase, adenylate kinase, monoamine oxidase, rotenone-insensitive NADH-cytochrome c reductase, succinate dehydrogenase, and cytochrome oxidase was severely depressed when compared to normal liver [30]. The gene discussed is PHGDH; the disease is neoplasm.