SIRT6 and breast neoplasm: In this regard, while SIRT6 up-regulation has been linked to paclitaxel/epirubicin resistance and increased in vitro invasion22,23, SIRT6 overexpression (SIRT6-OE) in basal-like breast tumor models was shown to both suppress the cancer stem cell (CSC) properties24 and to enhance tumorigenesis via oxidative phosphorylation25.