[complex, lipid-soluble, macrocyclic lactone produced by the Japanese soil bacterium Streptomyces tsukubaensis; experimental immunosuppressant which inhibits T-lymphocyte activation and fungal growth by binding to peptidyl prolyl isomerase, forming a complex which interferes with calcium signaling. ( CSP )] (UMLS (NCI) C0729218) FK506; =Organic Chemical; Pharmacologic Substance =Antibiotics; [IM600] IMMUNE SUPPRESSANTS