Nonetheless, because WGS of the tumor uncovered a somatic mutational signature that is broadly indicative of BRCA1/2 pathway disruption (48), this prompted us to explore DNA repair inhibitors, revealing remarkable efficacy of combined pharmacologic targeting of PARP1 and LIG3 in both therapy-naïve parental tumors and tamoxifen-resistant derivatives. Here, PARP1 is linked to neoplasm.