Since PGI/PGII ratio < 3 indicates AG, our Positive‐Gastric‐GIST‐PG‐CEA criteria (PGI < 70 ng/mL, PGI/PGII ratio ≥ 3.0, and CEA ≤ 5 μg/L) can distinguish GG from AG in most cases. This evidence concerns the gene CEACAM5 and gastrointestinal stromal tumor.