Moreover, the levels of MMP-9 in serum was found to significantly correlate with TNM staging [1,182 ng/ml (range, 692–1,932.25 ng/ml) vs. 894 ng/ml (572–1,586.25 ng/ml), respectively; P=0.021] (Fig. 3B) and lymph node metastasis [1,299.5 ng/ml (range, 740.25–1,994.5 ng/ml), vs. 691.5 ng/ml (range, 404.75–1,028 ng/ml), respectively; P<0.0001] (Fig. 3D). This evidence concerns the gene MMP9 and metastatic malignant neoplasm in the lymph nodes.