ENO2 and neoplasm: A total of 359 out of 374 patients were examined for serum tumor markers, and 73 had elevated levels of cytokeratin 211 (CYFRA211, reference range < 3.3 ng/ml), 40 had elevated carcinoembryonic antigen (CEA, <10 μg/l), 8 had elevated neuron-specific enolase (NSE, <20 ng/ml), and 1 had elevated pro-gastrin-releasing peptide (proGRP, <3 ng/ml), respectively.