The central role of the gastrointestinal tract in immunological reactions.
D000818:Animals; D000941:Antigens / Q000276:immunology; D001646:Bile / Q000378:metabolism; D004064:Digestive System / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D007114:Immunization; D007070:Immunoglobulin A / Q000378:metabolism; D007071:Immunoglobulin A, Secretory / Q000096:biosynthesis; D007073:Immunoglobulin E / Q000276:immunology
D000941:Antigens; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007073:Immunoglobulin E