ERBB2 and metastatic malignant neoplasm in the lymph nodes: The former includes lymph node metastasis, histological grade, the mutation of tumor suppressor genes and amplification of human epidermal growth factor receptor 2 (HER2) and the status of the estrogen and progesterone receptors, while the latter includes chemotherapy, radiotherapy, surgery, hormonal therapy and trastuzumab treatment [2].