PARP1 and cancer: Previous study has implied that DNA repair and Poly (ADP‐ribose) polymerase 1 (PARP1) protein expression may be upregulated in TNBC.[4, 5] PARP inhibitors (PARPi) mainly inhibit PARP1‐mediated DNA single‐strand break repair, which can lead to synthetic lethality in tumors carrying germline mutations in either Breast cancer susceptibility gene 1/2 (BRCA1/BRCA2) or other homologous recombination (HR)  factors.