SIRT3 and breast cancer: Additionally, Zou et al. demonstrated that the loss of SIRT3 (following treatment with SIRT3 shRNA) in MCF-7 breast cancer cells resulted in increased acetylation at lysine 413 of isocitrate dehydrogenase 2 (IDH2), a key enzyme in the Krebs cycle that oxidizes and decarboxylates isocitrate into α-ketoglutarate, and that SIRT3 loss decreases the level of IDH2 dimerization [67].