ERBB2 and breast cancer: Successful examples of targeted cancer drugs are the monoclonal antibody Trastuzumab (Herceptin®), which is used to treat breast cancer overexpressing human epidermal growth factor receptor 2 protein (HER-2) [3], and Vemurafenib (Zelboraf®), a small molecule inhibitor of B-RAF protein, for the treatment of patients with inoperable or metastatic melanoma [4].