CLDN1 and metastatic malignant neoplasm in the lymph nodes: In addition, CLDN1 mRNA expression was significantly higher in the tissue of NSCLC patients in advanced TNM stages (III–IV) and with the presence of lymph node metastases in comparison to subjects without lymph node metastasis and at stages I and II, what indicate the role for CLDN1 in the progression and metastasis of NSCL (15).