Effective treatments for HER2+ breast cancers include the monoclonal antibody trastuzumab [32], the antibody–drug conjugate ado-trastuzumab emtansine [33], and the dual tyrosine kinase inhibitor lapatinib which targets both the HER/neu and the epidermal growth factor receptor (EGFR) [34]. Here, ERBB2 is linked to breast cancer.