GRP and neoplasm: The 14 features mentioned above and the 5 serum tumor markers levels including ProGRP, VEGF, CEA, CYFRA21-1 and NSE from 208 patients were employed as the input variables to develop the C5.0-2, ANN-2 and SVM-2 models in the training set, which included 97 lung cancer and 111 lung benign disease patients.