Meanwhile, the cut-off value was 1.6252 after SPSS analysis, the corresponding Youden index was 0.5, the sensitivity (SEN) of tRF-17-18VBY9M was 69%, the specificity (SPE) was 83%, the overall accuracy (AUUC) was 74%, the positive predictive value (PPV) was 86%, and the negative predictive value (NPV) was 63%, which was superior to CEA, CA199, and CA724 overall, suggesting that serum tRF-17-18VBY9M could effectively distinguish gastric cancer patients from healthy donors. The gene discussed is CEACAM5; the disease is gastric cancer.