umls-concept:C0021054 | skos:definition | MSH: Biologically active substances whose activities affect or play a role in the functioning of the immune system.,CSP: substances whose activities affect or play a role in the functioning of the immune system; naturally or artificially synthesized immunologic agents, such as vaccines, toxins, toxoids, immune sera, antigens, cytokines, antitoxins, antibodies, immunoglobins, etc. | lld:umls |