Furthermore, by plotting the ROC curve, the calculated AUCs for serum CA125, AFP, CEA, and their combined detection in diagnosing the differentiation degree of gastric cancer were 0.819, 0.883, 0.746, and 0.986 (P<0.001), respectively, as shown in Table 4 and Figure 6. Here, CEACAM5 is linked to gastric cancer.