The univariate analysis suggested that clinical stage (p=0.006; HR=0.474, 95% CI 0.279 to 0.804) and FOXP3 levels on TILs (p=0.011; HR=2.352, 95% CI 1.221 to 4.531) were predictive factors for RFS in SCLC. Here, FOXP3 is linked to small cell lung carcinoma.