Furthermore, SMAD4 expression was lower in NSCLC, and a good prognosis in NSCLC (HR = 0.6, 95% CI = 0.51–0.72, P = 4.2 e-9) was shown to correlate with higher SMAD4 expression using the Kaplan–Meier Plotter database. This evidence concerns the gene SMAD4 and non-small cell lung carcinoma.