EGFR and metastatic malignant neoplasm in the lymph nodes: Furthermore, the significant proportions of uncorrelated EGFR, HER2, and HER3 expression levels between primary tumors and lymph node metastases indicate that it may not be appropriate to use genetic profiles of lymph node metastasis to guide treatment plans, given that genetic profiles of primary tumor are more widely-used to guide patient selection of targeted therapies in clinical trials46–50.