CDX2 and chronic atrophic gastritis: A proportion of people with established gastric atrophy develop intestinal-type metaplasia (see Glossary, Box 1) of the gastric mucosa over time, where oxyntic glands (see Glossary, Box 1) are replaced by CDX2 (caudal-type homeobox 2)-expressing glandular units, which are morphologically similar to the intestinal crypt.