CEACAM5 and gastric cancer: To establish an accurate method for evaluating the possibility of GC by using serum TMs, we obtained a classification discriminant equation using the multivariate logistic regression analysis to ascertain whether patients have GC as follows: Y = −2.185–0.015×1+0.180×2+ 1.226×3+1.505×4+2.749×5 (where X1 = Age, X2 = Sex, X3 = CEA, X4 = CA19-9 and X5 = CA72-4), for which the critical value is 0.50, thus, if the Y of a case is larger than 0.50, it belongs to the GC group.