ERBB2 and breast carcinoma: In addition, human epidermal growth factor receptor 2-positive (HER2+) breast cancer makes up about 20% of all invasive breast cancers, and Herceptin (trastuzumab), known as a human monoclonal antibody that interferes with the HER2 receptor, is currently the only FDA-approved therapeutic antibody for HER2-positive breast cancer (30) (31).