title: Recognition and selection.
mesh_terms: D000818:Animals; D000941:Antigens; D001665:Binding Sites; D002449:Cell Aggregation; D000939:Epitopes; D008214:Lymphocytes / Q000276:immunology; D009024:Morphogenesis; D010802:Phylogeny; D012641:Selection, Genetic; D013816:Thermodynamics; D014714:Vertebrates
chemical_list: D000941:Antigens; D000939:Epitopes