Gastrin is a gastrointestinal hormone secreted by the G cells of the antrum and duodenum, which plays an important role in regulating the function of the digestive tract and maintaining its structural integrity. In humans, more than 95% of the bioactive gastrin is alpha-aminated gastrin, mainly consisting of two isomers, G-17 and G-34, of which 80%-90% is G-17. G-17 is only secreted by G cells in the gastric antrum, so it is an important indicator of gastric mucosal injury.

Gastrin is a gastrointestinal hormone mainly secreted by the G cells of the antrum and duodenum, which plays an important role in regulating the function of the digestive tract and maintaining its structural integrity.

Pepsinogen (PG) is the precursor of pepsin that divided into pepsinogen I and pepsinogen II according to its biochemical and immunochemical properties. It is mainly secreted by mucous cells, the stomach body and the main cells of the stomach fundus.

Gastric diseases refer to various diseases that affect the structure and function of the stomach, including gastritis, gastric ulcers, and gastric cancer.

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Early detection and diagnosis are crucial for improving survival rates. In recent years, the combined use of gastric pepsinogen I (PGI), gastric pepsinogen II (PGII), gastrin-17 (G-17) assay kits together with that of Helicobacter pylori (H. pylori) antibodies has shown promise in the field of gastric cancer screening.

Gastric cancer is a global health burden, with high mortality rates due to late-stage diagnoses. However, recent advancements in medical research have led to the development of serological screening tests that had shown promising results in detecting gastric cancer at an early stage.