The levels of glycan antigen 199 (CA199), serum glycan antigen 125 (CA125), neuron-specific enolase (NSE), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), and gastrin-releasing peptide precursor (ProGRP) were not statistically significant in patients with different types of malignant lung nodules (P > 0.05). The gene discussed is ENO2; the disease is cancer.