The cut-off limits for RacGAP1-Average according to the ROC curve were determined as follows: TC-AC: 1.5% (AUC = 0.705, p = 0.019, sensitivity = 0.857, 1-specificity = 0.583), AC-SCLC: 13.5% (AUC = 0.897, p < 0.001, sensitivity = 0.875, 1-specificity = 0.238), AC-LCNEC: 17.5% (AUC = 0.918, p = 0.001, sensitivity = 1.000, 1-specificity = 0.143). This evidence concerns the gene RACGAP1 and small cell lung carcinoma.