Therapeutically active compounds included platinum derivatives and PARP inhibitors, for which genomic and/or functional HRD have been shown to predict responses in BC patients,6, 10, 11, 15 anthracyclines, for which sensitivities were reported in BRCA1/BRCA2‐deficient tumors30 as well as DNA synthesis inhibitors, since recent research has carved out critical roles of HR components in DNA replication fork protection and reactivation.23 Here, BRCA2 is linked to breast cancer.