MMP9 and metastatic malignant neoplasm in the lymph nodes: The results demonstrated no difference was founded between MMP9 polymorphisms and NSCLC with histological type, clinical stage, and lymph node metastasis parameters (p > 0.05), and there was no difference in clinical stage with MMP13 polymorphism (p > 0.05), but a significant association with histological type, clinical stage, and lymph node metastasis (p < 0.05).