Study population Eligible patients were 18 to 75 years of age and primary or secondary renal transplant recipients in their second year posttransplant with stable serum creatinine levels (i.e., < 20% variation for the previous 3 months). All patients must have received induction therapy, been corticosteroid-free for at least 3 months, and receiving combination maintenance therapy consisting of cyclosporine (trough level, 125 to 175 ng/mL) and mycophenolate mofetil (CellCept, F. Hoffmann- La Roche AG, Basel, Switzerland) 2 g daily.