Scholars Mo discusses the three tumor markers combined test value to the diagnosis of gastric cancer; the results showed that the levels of tumor markers gastric cancer group were obviously higher than that of control group; gastric cancer tumor markers combined detection sensitivity and accuracy were higher than pure detection, and CEA, CA199, and CA724 single detection has certain significance to the diagnosis of gastric cancer; the joint detection can improve the sensitivity and accuracy of diagnosis of gastric cancer [20]. Here, CEACAM5 is linked to gastric cancer.