Used in medicine to prevent organ rejection after transplantation, particularly in kidney, liver, and heart transplants. It works by suppressing the immune system, helping the body accept the new organ. Also used in cancer treatment, especially for advanced kidney cancer and certain types of breast and pancreatic tumors. Acts by inhibiting a key signaling pathway involved in cell growth and proliferation. Available as oral tablets or in coated-stent formulations to prevent re-narrowing of arteries after angioplasty.