In the present study, we analyzed these 8 serum factors after treatment, including calcium concentration, carcinoembryonic antigen (CEA), cancer antigen-125 (CA125), cancer antigen-153 (CA153), carbohydrate antigen-199 (CA199), cytokeratin fraction 21-1 (CYFRA21-1), total prostate-specific antigen (TPSA), and neuron-specific enolase (NSE), to clarify their prognostic value in predicting liver metastasis in 1746 patients with lung cancer. Here, ENO2 is linked to lung carcinoma.