In addition to BRCA1 and 2 mutations, aberrations in other genes (incl PALB2 [85,86], BRCAness [40] and/or high extent of structural rearrangement [5], may lead to loss of functional HR, and importantly, may sensitise these cancers to specific DNA-damaging treatments, including poly(ADP-ribose) polymerase (PARP) inhibitors and DNA-intercalating agents (mitomycin C, platinum-based combinations). This evidence concerns the gene BRCA1 and cancer.