BRCA1 and breast ductal adenocarcinoma: Recent studies have indicated that positive staining for 'basal' markers in patients with familial breast and/or ovarian tumours is strongly predictive of carrying a BRCA1 mutation [27,34,41]; however, there are several lines of evidence to suggest that sporadic basal-like ductal carcinomas do not harbour BRCA1 somatic mutations [42].