Targeted therapies for cancer are designed to inhibit speci c cellular changes or signals required for tumour cells to proliferate, survive, promote angiogenesis and metastasize. Examples include trastuzumab (a monoclonal antibody that targets the human epidermal growth factor receptor 2 [HER2]), imatinib ( a small molecule inhibitor of bcl-abr, an oncogenic kinase) and cetuximab ( a monoclonal antibody that binds to the extracellular domain of the epidermal growth factor receptor [EGFR]).