Rapamycin

Rapamycin is an antibiotic that blocks a protein involved in cell division and inhibits the growth and function of certain T cells of the immune system involved in the body's rejection of foreign tissues and organs. It is a type of immunosuppressant and a type of serine/threonine kinase inhibitor. Rapamycin is now called sirolimus.

Rapamycin, or sirolimus (INN), is an immunosuppressant drug used to prevent rejection in organ transplantation. It is especially useful in kidney transplants. Sirolimus is a macrolide and was first discovered as a product of the bacterium Streptomyces hygroscopicus.