CCR9 and metastatic malignant neoplasm in the lymph nodes: Moreover, upon the univariate analysis using the cox proportional hazards model, positive lymph node metastasis (HR = 1.71, P = 0.021), advanced TNM stage (HR = 2.184, P = 0.002), postoperative chemotherapy (HR = 0.628, P = 0.044) and positive CCR9 expression (HR = 2.189, P = 0.007) were associated with increased risk of death in the patients with lung adenocarcinoma.