Umirolimus is a semi-synthetic macrocyclic lactone prepared from rapamycin by selective alkylation of the 42-hydroxy group, providing one of most hydrophobic tacrolimus analogues. Umirolimus has been targeted for use in stents and medical devices to suppress localised immunoreaction. Like all tacrolimus analogues, umirolimus binds to receptor protein, FKBP12. The complex then binds to mTOR and prevents it from interacting with target proteins. Umirolimus is extensively cited in the literature with over 70 citations.