The positive rate of MTA3 protein expression was significantly higher in NSCLC samples (59.32%, 70/118) than that in non-neoplastic samples (0.00%, 0/118), and in NSCLC samples with lymph node metastasis (79.59%, 39/49) was higher than that in NSCLC samples without lymph node metastasis (44.93%, 31/69) (P =0.000). This evidence concerns the gene MTA3 and metastatic malignant neoplasm in the lymph nodes.