Lakhani and colleagues [17] studied the pathology of 82 familial breast cancers not attributable to BRCA1 or BRCA2 mutations, and they found these non-BRCA1/2 cancers to be of lower grade, to show less pleomorphism and to have a lower mitotic count than sporadic cancers or BRCA mutation-positive cancers. This evidence concerns the gene BRCA1 and breast carcinoma.