CEACAM5 and gastric cancer: Scholar Fan studied the value of tumor markers C12 system in gastric cancer, using univariate and multivariate evaluation of tumor markers clinicopathologic correlation; using chi-square test to select key tumor markers in the diagnosis of gastric cancer is the most favorable combination; the result shows that the tumor marker biochip system has an important diagnostic value for gastric cancer, and CA19-9, CA242, CEA, and CA125 are four key indexes for tumor diagnosis [19].