MMP9 and metastatic malignant neoplasm in the lymph nodes: However, we observed that the expression level of MMP9 was positively correlated with the status of lymph node metastasis (N classification) (N0 vs. N1) (P =0.00), and clinical stage (I-II vs. III-IV) (P = 0.00) in OSCC patients ( Table 1).