Photofluorography, serum pepsinogen concentration, serum ghrelin (low serum ghrelin may indicate a high risk of GC), gastrin 17, and gastric wall cell antibodies (associated with an increased risk of atrophic gastritis, which may play a role in GC) are among the non-invasive ways of screening for stomach cancer to date [22]. The gene discussed is GHRL; the disease is chronic atrophic gastritis.