BRCA2 and breast cancer: However, we demonstrated that Signature 3 is not necessary to explain the mutational patterns of MM samples, which furthermore do not show a genomic landscape consistent with BRCA1/BRCA2 loss and its related HRD in terms of 96-class profiles, number of microhomology-mediated deletions and internal tandem duplications as compared to breast cancer (Fig. 3b, c and Supplementary Figs. 5 and 6).