title: Chemical signals in the immune system.
mesh_terms: D000818:Animals; D006801:Humans; D007109:Immunity; D007376:Interleukin-2 / Q000502:physiology; D008214:Lymphocytes / Q000276:immunology*; D008222:Lymphokines / Q000502:physiology*; D008264:Macrophages / Q000276:immunology
chemical_list: D007376:Interleukin-2; D008222:Lymphokines