CEACAM5 and gastric cancer: Of the reported biomarkers for stomach cancer, i.e., carbohydrate antigen (CA)72-4, carbohydrate antigen (CA)12-5, BCA-225, alpha-fetoprotein, SLE, hCG, and pepsinogen I/II, carcinoembryonic antigen (CEA) and CA19-9 are the most common biomarkers in practical use.