HER2 is targeted by the monoclonal antibody trastuzumab (HerceptinTM) in breast cancers [24, 25], where it is overexpressed in approximately 20-25% of cases and this approach is now clinically approved for the treatment of breast cancer patients expressing HER2 at high levels (+3 herceptestTM). The gene discussed is ERBB2; the disease is breast carcinoma.