Olaparib, a PARP inhibitor, was approved for human epidermal growth factor receptor type 2 (HER2)-negative locally advanced or metastatic breast cancer with germline BRCA1/2 mutations, and as maintenance therapy for platinum-sensitive advanced ovarian cancer with germline mutations in DNA repair genes BRCA1/2 [42, 43]. Here, ERBB2 is linked to ovarian cancer.