Thus, we performed a ROC analysis on the data of 124 GC patients and 50 gastritis patients, and we discovered that the AUC of tRF-23-Q99P9P9NDD was 0.685 (95% CI 0.605–0.766), which was higher than the 0.678 (95% CI 0.594–0.761) for CEA, 0.605 (95% CI 0.512–0.697) for CA199, and 0.676 (95% CI 0.594–0.757) for CA724 (Fig. 5G). The gene discussed is CEACAM5; the disease is gastric cancer.