In a single arm study of adjuvant docetaxel and cyclophosphamide plus trastuzumab in patients with HER2-amplified breast cancer, patients with or without TOP2A amplified had excellent prognoses (3-year DFS; TOP2A amplified vs. normal/deleted, 97.2% vs. 96.4%) [33]. The gene discussed is ERBB2; the disease is breast cancer.