PLK1 and breast cancer: The utilization of PLK1 inhibition as an approach for treating TNBC and BRCA defined cancers and the clinical association between PLK1 and PARP in our cohort intrigued us to explore whether combinatorial, sequential inhibition of PLK1 and PARP might be a good therapeutic approach to extend the potential effect of PLK1 inhibitor beyond BRCA deficient BC.