The aim of our study was to determine the prevalence of the selected pro-inflammatory cytokine polymorphisms in the Slovenian population of patients with gastric cancer and chronic gastritis, and compare its prevalence with the prevalence in the normal healthy population, to see if high incidence of gastric cancer in Slovenian population could be, at least partially, attributed to the higher prevalence of those proinflammatory polymorphisms in the genes for IL-1β, IL-1ra, TNF-α and TLR-4. The gene discussed is TNF; the disease is gastric cancer.