There was no significant difference between CDK4 amplification and CDK4 non-amplification group regarding sex (P = 0.987), age (P = 0.588), grade (P = 0.403), invasive depth (P = 0.791), vessel (P = 0.592) and nerve invasions (P = 0.511), lymph node metastasis (P = 0.556), anatomic site (P = 0.768), smoking (P = 0.748), and clinical stage (P = 0.625). The gene discussed is CDK4; the disease is metastatic malignant neoplasm in the lymph nodes.