Due to the high prevalence of Helicobacter pylori infection in the Iranian population, the study of factors involved in the pathogenicity of this bacterium, the study of immune responses of host people to its immunogenic antigens, production of recombinant immunogenic proteins in order to design diagnostic kits and population screening as well as vaccine design against this infection and study of etiological factors in the occurrence of gastrointestinal problems and disorders caused by this bacterium, including chronic gastritis, gastrointestinal ulcers and gastric adenocarcinomas are the most important activities of this research group. Risk of death and complications from gastric cancer as a disease caused by chronic infection with Helicobacter pylori has led the groups research into early detection of gastric cancer using genomics and proteomics tools. In this regard, three factors, including environment, host and pathogen, are examined simultaneously. To achieve these goals, the Helicobacter pylori Research Group is implementing several national and international projects.