SMAD4 and non-small cell lung carcinoma: We summarize them as follows: 1) this study did not discuss SMAD4 at the genetic level, such as the mutation of Smad4 in NSCLC; 2) this study did not involve the study of Smad4 signaling mechanism in NSCLC; and 3) the population in this study was all Chinese, which may lead to a risk of regional and ethnic deviation.