 Most liver transplant recipients receive an immunosuppressive drug regimen that contains either cyclosporine or tacrolimus. Although these drugs have revolutionized transplantation, in many patients their long-term use is a major cause of serious side effects, including kidney failure, hypertension, diabetes mellitus, hyperlipidemia, andor neurologic side effects. Stopping or reducing the dose of cyclosporine or tacrolimus can ameliorate the above side effects but may increase the risk of rejection. Mycophenolate mofetil MMF, a safe and effective immunosuppressant that does not cause the above side effects, is typically used in combination with cyclosporine or tacrolimus. Attempts in liver transplant recipients at using mycophenolate mofetil alone or with reduced dose cyclosporine or tacrolimus have been successful but some patients developed rejection, and a few patients suffered liver failure. Most rejections after liver transplantation are easy to successfully treat with increased immunosuppression, but such treatment may carry risks such as increased susceptibility to infection. There have not yet been any large trials to adequately assess the safety and efficacy of using mycophenolate mofetil this way alone or with reduced dose calcineurin inhibitor CNI. 