In this respect, HRD causes specific mutational scars in the genome that can be detected via massive parallel sequencing, such as single base substitution (SBS) signatures 3 and 8 (SBS3 and SBS8), small insertion/deletion (ID) signature (ID6) and structural variant (SV) signatures 3 and 5 (SV3 for BRCA1-type cancers and SV5 for BRCA2-type cancers) [20,21,22]. This evidence concerns the gene BRCA1 and cancer.