SMAD4 and metastatic malignant neoplasm in the lymph nodes: And SMAD4 mutant patients were more likely to feature mucinous differentiation (pooled OR = 2.23; 95%CI 1.85–2.70, P = 0.000), tumors are more likely to occur in the colon (pooled OR = 1.15; 95% CI 1.01–1.31; P = 0.042), more prone to lymph node metastasis (N1 + N2/N0; pooled OR = 1.42; 95% CI 1.20–1.67; P = 0.000), and to harbor concurrent RAS mutations (pooled OR = 2.13; 95% CI 1.37–3.34; P = 0.001).