Sometime before starting phase 2, patients will provide a 24-hour urine collection to test for kidney function. The day before starting phase 2, they will have a cannula (small needle) inserted into an arm vein for about 12 hours to draw blood samples-one before starting the ganciclovir infusion, then at 15, 30, 60, and 90 minutes, and 2, 4, 6, 8, and 12 hours after the dose.