title: The immune system--some basic concepts.
mesh_terms: D000906:Antibodies / Q000276:immunology; D000916:Antibody Diversity; D000917:Antibody Formation; D000941:Antigens / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D006801:Humans; D007109:Immunity; D008285:Major Histocompatibility Complex; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D000941:Antigens