ERBB2 and breast cancer: While the luminal (ER/PR positive) and the HER2-positive (with amplified HER2 expression) breast cancer patients could be benefited from endocrine and HER2-targeted therapies7, chemotherapy is the only therapeutic option currently available for basal-like (also called triple negative breast cancers or TNBC, no expression of ER, PR, and HER2)8 breast tumors.