Rapamycin binds to the cytosolic protein FK-binding protein 12 (FKBP12) and inhibits mTOR pathway by directly binding to the mTOR Complex1 (mTORC1). Rapamycin has variety of usages in vitro and in vivo. It is an immunosuppressant drug used to prevent rejection in organ transplantation. It showed lifespan extension in mice. Its antiproliferative effects led to treat tuberous sclerosis complex and several cancers.