The gut as a lymphoid organ.
D000818:Animals; D000917:Antibody Formation; D001065:Appendix / Q000166:cytology / Q000276:immunology; D001402:B-Lymphocytes; D002417:Cattle; D002452:Cell Count; D002465:Cell Movement; D004064:Digestive System; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D051379:Mice; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology; D011817:Rabbits; D051381:Rats; D013601:T-Lymphocytes