CEACAM5 and lung cancer: A number of diagnostic biomarkers for lung cancer have been suggested, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cytokeratin 19 (CYFRA-21-1), alpha-fetoprotein (AFP), serum carbohydrateantigen-125 (CA-125), carbohydrate antigen-19.9 (CA-19.9), and ferritin [14, 16].