This overexpression determines chemoresistance mediated by an increase in CD133 + cancer stem cells, overexpressing PARPs and SIRT1, and the treatment with FK866 in combination with olaparib (PARP inhibitor) or sirtinol (SIRT inhibitor) is able to counteract tumour progression (Lucena-Cacace et al., 2018). Here, PARP1 is linked to cancer.