CEACAM5 and lung cancer: Some of the serum/plasma tumor markers recently developed for the detection, diagnosis, prognosis, or management of lung cancers include cytokeratin 19 fragments (CYFRA 21-1), carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR), soluble mesothelin-related proteins (SMRP), and Osteopontin (pOPN) [123,124,166,167].