S100A8 and peptic ulcer disease: Compared to those infected with CagA-negative H. pylori strains, patients with a CagA-positive H. pylori infection have a higher risk of gastric cancer or peptic ulcer disease.45 Xie et al. revealed autophagy was decreased in the duration of H. pylori infection in a CagA-dependent manner, resulted in ubiquitination degradation of RAD51 and genomic instability in gastric cells, which inducing progression of gastric epithelial cells to cancer.45 VacA is a cytotoxin encoded by the vagA gene; its main function is cell vacuolation through pores on the epithelial cell membrane.