Is rapamycin sirolimus?

Sirolimus, also known as rapamycin and sold under the brand name Rapamune, is a macrolide compound used to coat coronary stents to prevent organ transplant rejection and to treat a rare lung disease called lymphangioleiomyomatosis. It has immunosuppressive functions in the human body and is especially suitable for preventing kidney transplant rejection. It is a mechanistic target of rapamycin kinase (mTOR) inhibitors that inhibits the activation of T cells and B cells by reducing their sensitivity to interleukin-2 (IL-2). Compared with calcineurin inhibitors, the main advantage of sirolimus is its low toxicity to the kidneys.