In addition to the presence of germline mutations at BRCA1 and BRCA2, recent studies have shown that mutations at somatic BRCA1, BRCA2, or germline PALB2, can also predict response to the PARP inhibitor olaparib in breast cancer [15], opening the door for the evaluation of other genes of the homologous recombinant pathway as potential biomarkers. This evidence concerns the gene BRCA2 and breast cancer.