Carcinoembryonic antigen (CEA) is a tumor marker in lung cancer and is used as a prognostic and predictive marker. CEA is a glycoprotein that involved in cell adhesion, and is normally produced during fetal development and the production of the CEA often stops before birth. CEA is a glycosyl phosphatidyl inositol (GPI)-cell surface anchored glycoprotein whose specialized sialofucosylated glycoforms serve as functional colon carcinoma L-selectin and E-selectin ligands, which may be critical to the metastatic dissemination of colon carcinoma cells.