SMAD4 and non-small cell lung carcinoma: SMAD complexes regulate the expression of target genes and are involved in many processes, such as inflammation and apoptosis.[6,7] Accumulative studies have shown that SMAD4 is involved in tumor invasion, metastasis and prognosis various tumors, such as cholangiocarcinoma and pancreatic cancer.[8,9] Moreover, many studies have detected the clinicopathological and prognostic significance of SMAD4 expression in NSCLC patients, but the potential clinicopathological value of Smad4 in NSCLC is inconsistent.