The levels of all serum tumor markers examined, including carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), squamous cell carcinoma antigen (SCC), neuron-specific enolase (NSE), cytokeratin fragment (CYFRA), and pro-gastrin-releasing peptide (Pro-GRP), were within the normal ranges. Here, ENO2 is linked to neoplasm.