PARP1 and breast cancer: Breast cancers with BRCA1 mutations include many TNBCs, however PARP inhibitors have not shown a direct correlation of effectiveness directly related to BRCA1 and BRCA2 mutations in TNBCs.36 MDA-MB-468 cells and HCC70 cells do not have BRCA mutations and they are more sensitive to PARP inhibitors than some breast cancer cell lines that have BRCA mutations.