In the gastric epithelial cells, CagA is transmitted through a unique type IV secretory system to the initial immune response, followed by a series of responses to recruit immune cells to form chronic gastritis, and serum CagA and VacA virulence proteins increase the risk of non cardia cancer, while the risk of low virulence protein of H. pylori is lower29,30. The gene discussed is S100A8; the disease is chronic gastritis.