Everolimus is a semi-synthetic macrocyclic lactone prepared from rapamycin by selective alkylation of the 42-hydroxy group with a silyl-protected hydroxyethyl triflate moiety, followed by addition of an ethylhydroxy moiety to provide greater stability and bioavailability. Like all tacrolimus analogues, everolimus binds to receptor protein, FKBP12. The complex then binds to mTOR preventing it from interacting with target proteins. Everolimus is extensively cited in the literature with over 2,000 citations.