PARP1 recognizes strand breaks, binds to the DNA backbone, recruits acceptor proteins, post-translationally modifies them by transferring PAR polymers (PAR-ylation) and also undergoes auto-PAR-ylation [2,3].Importantly, in cases of defective double strand DNA damage repair mechanisms (homologous recombination), possibly due to mutated Breast Cancer 1/2 (BRCA1/2mut) proteins, PARP1-mediated processes can take over the repair [2,4]. This evidence concerns the gene PARP1 and breast cancer.