The first targeted anti-neoplastic agent, Trastuzumab (Herceptin©), a monoclonal antibody to ERBB2, produces a response in approximately 15% of heavily pretreated patients with metastatic BC as a single agent [5] and in combination with chemotherapy improved the overall survival of patients with metastatic BC by 5 months [6]. The gene discussed is ERBB2; the disease is breast cancer.