In addition, all the above-mentioned enzymes as well as citrate synthase (CS) succinyl-CoA synthetase (SCS), fumarate hydratase (FH) and MDH2 presence in the nucleus of mouse liver cells, human hepatoma HepG2 cells and human breast adenocarcinoma MCF7 cells has also been reported (Liu et al., 2021). Here, CS is linked to breast adenocarcinoma.