Consistent with the notion that SIRT6 is well suited to catalyze mono-ADP ribosylation we recently reported that overexpression of SIRT6 selectively induces massive apoptosis in cancer cells but not non-cancerous cells and that this cytotoxicity is dependent on the mono-ADP ribosylation activity of SIRT6 [15]. This evidence concerns the gene SIRT6 and cancer.