Signature 3 is defined by an elevated number of large (longer than 3bp) insertions and deletions with overlapping microhomology at breakpoint junctions and are known to be associated with mutations in BRCA1 and BRCA2 or deficiency of a homologous recombination (HR) repair system in breast, pancreas and ovarian cancer [46,47]. This evidence concerns the gene BRCA2 and ovarian cancer.