It is known that H. pylori-associated gastric cancer has a strong connection with gastritis, especially chronic atrophic gastritis of the corpus or type AB gastritis, where Th1-type CD4 cells and their product interferon-gamma (IFN-γ) may play a critical role, along with other pro-inflammatory cytokines such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNFα). This evidence concerns the gene IFNG and chronic atrophic gastritis.