An immunohistochemical study of MMP-2 in 46 patients with OSCC found a high level of expression in 77% of patients with lymph node metastases, but only in 25% of patients without lymph node metastases[26].Another two immunostaining researches of MMPs also revealed a strong expression of MMP-2 and MMP-9 in OSCC patients with lymph node metastasis[27], [28]. The gene discussed is MMP9; the disease is metastatic malignant neoplasm in the lymph nodes.