4. Treatment of acute rejection episodes: mild to moderate acute rejection episodes: re-start 1-2 daily doses of tacrolimus. Severe acute rejection episodes or those mild to moderate episodes that do not improve after 10 days of treatment: 1-2 daily doses of tacrolimus plus methylprednisolone 0.5-1 g for 3 days. Resolution of the rejection episode will be followed by resumption of the above mentioned protocol. If a new rejection episode takes place, after treatment of the acute episode no further attempts to reduce tacrolimus dosages will be attempted. In all cases rejection will be confirmed by liver biopsy.