CD274 and metastatic malignant neoplasm in the lymph nodes: The results of statistical analysis showed that the positive expression of PD-L1 protein was correlated with lymph node metastasis (P = 0.028), while there was no significant correlation with gender, age, pathological type, TNM stage, and pathological differentiation degree of NSCLC patients (P > 0.05) (Table 3).