title: Immunology: Immunity's ancient arms.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Litman
authors.forename: John P
authors.initials: JP
authors.lastname: Cannon
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D005075:Biological Evolution; D006801:Humans; D007798:Lampreys / Q000276:immunology* / Q000378:metabolism; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D011971:Receptors, Immunologic / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D011971:Receptors, Immunologic