<h4>Background</h4>High-grade serous ovarian cancer (HGSOC) and triple-negative breast cancer (TNBC) frequently exhibit mutations in DNA damage response (DDR) genes, as <i>BRCA1, BRCA2</i> and <i>TP53</i>, which are associated with chemotherapy sensitivity. This evidence concerns the gene TP53 and triple-negative breast carcinoma.