Although other mechanisms, such as impaired DNA repair ability and reduced β-catenin, cyclin D1 or NF-κB activity could also have contributed to the antitumor effects of low SIRT6 in our BC models, as suggested by earlier reports [16, 17], our findings complement these previous studies and depict a novel, key role for SIRT6 in BC metabolism. Here, CCND1 is linked to breast cancer.