Chemotherapy with paclitaxel/docetaxel (if not used in prior treatment), nab-paclitaxel and vinorelbine is described to be commonly acceptable for HER2-negative metastatic breast cancer (MBC) with prior anthracyclines/taxane, which is described in the Japanese chemotherapy guideline for breast cancer in the first or second treatment line (The Japanese Breast Cancer Society Clinical Practice Guideline for Systemic Treatment of Breast Cancer in Japanese). The gene discussed is ERBB2; the disease is breast carcinoma.