Of the six BRCA1 mutation-associated breast cancers with information on histopathology, hormone receptor status and HER2 status, four were triple-negative (ER/PR/HER2-negative) invasive ductal carcinomas and two were atypical medullary breast cancers (ER/PR-positive, HER2-negative). This evidence concerns the gene ERBB2 and medullary breast carcinoma.