ERBB2 and breast cancer: Lapatinib (Tykerb) is a small-molecule inhibitor of kinase activity for both EGFR (HER-1) and HER-2 [8, 9] that has found use in breast cancer treatment in combination with chemotherapeutic agents [10, 11] and with the HER-2-directed monoclonal antibody drug trastuzumab [12, 13].