By analyzing serum samples from 129 patients with GC, 55 gastritis patients, and 116 healthy subjects, we established a diagnostic model combining STARD4-AS1 with serum CEA (arcinoembryonic antigen), CA199 (carbohydrate antigen 199), and CA724 (carbohydrate antigen 724) to assess its effectiveness in diagnosing GC. This evidence concerns the gene CEACAM5 and gastric cancer.