ERBB2 and neoplasm: Over the past years, there has been a proliferation of agents designed to inhibit single PTK in tumor, including those directed against Bcr-Abl (e.g. imatinib mesylate)[6], epidermal growth factor receptor (EGFR, e.g. erlotinib)[7], HER-2/neu (e.g. trastuzumab)[8].