CEACAM5 and lung carcinoma: Many serologic biomarkers of lung cancer have emerged recently: these include carcinoembryonic antigen (CEA), the cytokeratin 19 fragment CYFRA21-1, cancer antigen CA-125 [109], plasma kallikrein [110], progastrin-releasing peptide (ProGRP), and neuron-specific enolase (NSE) [111].