CEACAM5 and neoplasm: The serum tumor markers carcinoembryonic antigen and neuron-specific enolase have a certain role in the diagnosis of lung cancer and can also be used as indicators of tumor recurrence after surgical intervention and chemotherapy; however, they have high false positive rates due to benign tumors, pregnancy, chronic inflammatory diseases, or other factors, reducing their reliability (Jiang et al., 2018).