Sirolimus is a potent immunosuppressive agent which has been proven to prolong graft survival in many animal models of transplantation. Sirolimus prevents both proliferation and migration of smooth muscle cells (in vivo and in vitro) in graft and balloon injury models. Furthermore, Sirolimus has been shown to be effective in reducing restenosis and the need for repeat revascularization while demonstrating superior efficacy measures such as angiographic late loss and binary restenosis.