ERBB2 and metastatic malignant neoplasm in the lymph nodes: Previous studies have used various factors to predict lymph node metastasis [8–11] such as magnetic resonance spectroscopy, DNA microarray assay for gene expression in breast cancer tissues, and P53 and Ki67 in patients with estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer [9, 12, 13].