ER-positive breast cancers are mainly treated via targeted endocrine therapy.3,4 HER2-/neu-overexpressing breast cancer patients are treated with the monoclonal antibody trastuzumab.5 Generally, chemotherapy and/or radiation is recommended for triple-negative breast cancers (TNBCs).6 However, it is well-known that many patients demonstrate intrinsic or de novo resistance to these therapies.7–9 Consequently, it is necessary to identify novel therapeutic targets. Here, ERBB2 is linked to triple-negative breast carcinoma.