Fig. 6

Correlation between clinical features and Smad4 expression in NSCLC tissues. a Expression of Smad4 was lower in NSCLC tissues than in normal lung tissues adjacent to cancer (P = 0.009). b Expression of Smad4 was lower in poorly differentiated NSCLC than in moderately and well differentiated NSCLC (P = 0.006). c NSCLC patients with lymph node metastasis (N2–N3) had a lower Smad4 expression than patients with lymph node metastasis (N0–N1) (P = 0.010). f NSCLC patients at stage IIIA showed a lower Smad4 expression than patients at stages IA–IIB (P < 0.001). NSCLC, non-small cell lung cancer; LAC, lung adenocarcinoma. LSCC, lung squamous cell carcinoma. N, node stage (TNM classification)