BRCA1 and breast neoplasm: Some breast tumours with the “BRCAness” feature may arise when expressions of BRCA1 or BRCA2 are repressed by hypermethylation or somatic mutation14, or when the homologous recombination pathway is abrogated through mutations in other genes in the pathway (e.g. PALB2)15,16, and there are ongoing clinical studies that seek to expand the utility of PARP inhibitors in this context17.