ERBB2 and breast carcinoma: In terms of IHC phenotypes, 13 (2.3%) of the BRCA1 mutant breast cancers were HR+/HER2−, 3 (3.3%) were HR+/HER2+, 2 (2.6%) were HR−/HER2+, and 9 (6.9%) were HR−/HER2−.