PD-L1 was highly expressed in male patients and smokers with lung adenocarcinoma (P = 0.019 and 0.002, respectively), while no associations were identified between PD-L1 expression and age, tumor size, clinical stage, positive pleural invasion, lymph node metastasis, or therapy methods. This evidence concerns the gene CD274 and metastatic malignant neoplasm in the lymph nodes.