Western blotting was then performed to detect the TCA cycle-associated enzymes using antibodies against CS, ACO2, IDH3A, OGDH, succinyl-CoA ligase GDP-forming beta subunit (SUCLG2), succinate dehydrogenase complex flavoprotein subunits A and C (SDHA and SDHC), fumarate hydratase (FH), and malate dehydrogenase 2 (MDH2) in the isolated mouse liver nuclei, as well as in nuclei isolated using the same protocol from human hepatocellular carcinoma cell line HepG2 and human mammary adenocarcinoma cell line MCF-7. This evidence concerns the gene MDH2 and breast adenocarcinoma.