CXCL8 and stomach disorder: In light of previous findings that gene polymorphism of proinflammatory cytokines are important genetic factors of the host in H. pylori infection and that acquisition may have occurred during childhood, this study seeks to assess whether the -251 (T>A) polymorphism of IL-8 is correlated with the etiology of gastric disease and/or with H. pylori infection in pediatric and adolescent patients in Brazil.