SMAD4 and metastatic malignant neoplasm in the lymph nodes: And the expression of Smad4 in NSCLC tissues with N2–N3 stage (20%; 3/15) of lymph node metastasis was lower than in NSCLC tissues with N0–N1 (59.5%; 22/37) stage (P = 0.010) (Table 6; Fig. 6c).