['The homeobox gene CDX2 is implicated in the appearance of intestinal metaplasia in Helicobacter pylori gastritis. The aim of this study was to investigate whether CDX2 expression in gastric mucosa occurs before the appearance of overt intestinal metaplasia in H. pylori gastritis, and whether or not this expression is reversible.', 'CDX2 was studied by immunohistochemistry in a cohort of 38 patients with H. pylori gastritis before and after eradication (mean follow-up 6.3 years) of H. pylori. A cohort of 49 individuals with healthy stomachs was analysed as a control.', 'In the control group no immunostaining of CDX2 in the epithelial cells of the gastric body was found, while in 57% of the cases a mild, aberrant nuclear immunostaining of CDX2 in the non-metaplastic epithelial cells in antrum, designated as "positive staining of single cells" (PSSC), was found. In H. pylori gastritis, the PSSC was seen in antrum and corpus in 100% and 26% of the cases, respectively. The prevalence of antral PSSC was significantly increased (on average by 4-fold) in H. pylori gastritis as compared with controls. After eradication of H. pylori, the prevalence of PSSC decreased significantly in antrum but not in corpus.'] Does helicobacter pylori infection induce a reversible expression of the CDX2 transcription factor protein in human gastric epithelium?