Furthermore, identifying breast cancer patients with homologous recombination deficiencies associated with germline mutations other than BRCA1/2 mutations seems to be necessary for the design of therapies based on synthetic lethality and for the interpretation of results of clinical trials aimed at evaluating the response to PARP inhibitors (or PARP inhibitors combined with chemotherapy regimens), not only in TNBC patients but also in those with Hn-TNBC. This evidence concerns the gene PARP1 and breast cancer.