Anti-gastric lining cell antibody is a kind of autoimmune antibody, positive means that there are antibodies in the body, which can be seen in atrophic gastritis, gastric cancer, pernicious anemia, hyperthyroidism and so on. Gastric lining cells can secrete gastric acid and endogenous factors, of which gastric acid helps digest food, and endogenous factors can combine with vitamin B₁₂ in food to form an indigestible complex, and vitamin B12 can be absorbed only when this substance reaches the ileum. When anti-mural cell antibodies are present in the body, they can lead to a decrease in the number of cells in the stomach lining and a decrease in gastric acid secretion, causing atrophic gastritis. In addition, a decrease in internal factors can cause a decrease in vitamin B₁₂ absorption, leading to megaloblastic anemia, or pernicious anemia. In addition gastric cancer, hyperthyroidism and other diseases, can also produce this antibody, leading to antibody positivity. When anti-gastric lining cell antibodies are present, it is recommended to seek prompt medical attention to clarify the diagnosis and standardize the treatment.