SIRT6 and breast carcinoma: Corroborating the tumor-promoting activities of SIRT6, a recent study demonstrated that SIRT6 deletion downregulated the expression and activity of pyruvate dehydrogenase and oxidative phosphorylation-related genes, suppressed the activity of respiratory complexes, and reduced the ATP/AMP ratio in MDA-MB-231 and MCF7 breast cancer cells [80].