In this context, Polak and coworkers have explored DNA signatures in a large cohort of 992 breast cancers and detected four recurrent signatures: (i) signature 1 (C > T at CpG sites); (ii) APOBEC-related signatures; (iii) signature 6, associated with microsatellite instability; and, (iv) a uniform signature, similar to signature 3, which is associated with BRCA1 and BRCA2 mutations [133]. Here, BRCA1 is linked to breast cancer.