Siromus 1 mg Tablets Siromus contains Sirolimus, an immunosuppressive agent that inhibits T-lymphocyte activation and proliferation by binding to immunophilin FKBP-12 and inhibiting the mammalian target of rapamycin (mTOR) pathway. It is indicated for the prevention of organ rejection in adult patients receiving kidney transplants and for treating lymphangioleiomyomatosis (LAM).