There were no significant differences between the training and validation sets in terms of age (P = 0.2244), TLG (Total Lesion Glycolysis) (P = 0.9373), tumor size (P = 0.0747), smoking history (P = 0.3849), pathological stage (P = 0.0675), tumor location (P = 0.4201) and carcinoembryonic antigen (CEA) level (P = 0.4076). The gene discussed is CEACAM5; the disease is neoplasm.