The expression of TrkB in NSCLC examined by immunohistochemistry. TrkB immunostaining in lung squamous cell carcinoma with (A) and without (B) lymph node metastasis. TrkB immunoreactivity in lung adenocarcinoma with (C) and without (D) positive nodes. It was suggested that TrkB expression was correlated with lymph node status. Original magnification, all ×400.