The advent of new immunosuppressive drug regimens has produced a substantial improvement in organ-allograft survival during this decade.^{1 2 3 4 5} However, the treatment of organ-transplant recipients still involves the lifelong use of immunosuppressive drugs such as cyclosporine and steroids to maintain graft function.^{1 2 3 4 5} Side effects associated with the long-term use of cyclosporine include nephrotoxicity, hepatotoxicity, neurotoxicity, hypertension, hypertrichosis, gingival hypertrophy, and lymphoid cancers.^{6 , 7} The cumulative toxicity of long-term steroid therapy can lead to hypertension, diabetes, osteoporosis, aseptic necrosis of bone, infection, fluid retention, and increased capillary fragility.^{8 , 9} A continued goal in organ transplantation is to eliminate these side effects by withdrawing maintenance . . .