Lack of CCR7 causes hypertrophic gastropathy that resembles Menetrier disease. Comparison of gastric mucosa histology between CCR7^−/−, CXCR5^−/−, and wt mice shows thickening (hypertrophy) of the mucosa of CCR7^−/− mice between 9 weeks and 18 months of age. Progressive mucosal hyperplasia with dilated cysts lined with a single layer of cuboidal epithelium was regularly observed in the gastric fundic mucosa of aged CCR7-deficient mice (10 to 18 months). Wt and CXCR5^−/− mice showed minimal or no pathomorphologic changes from 9 weeks to 18 months of age. One representative mouse is shown of 6 to 8 mice per group. Original magnification, ×100; HE staining in paraffin-embedded sections.