This protocol follows closely previous studies in this series. Three additional modifications will be made however: 1) The first T cell add-back will be delayed until day 60 (instead of day 45) so as to continue to allow a 45 day period without cyclosporine immunosuppression. 2) No day 100 T cell add-back will be given. (In previous studies many patients have, for protocol-defined reasons, not received the second transfusion and there is no evidence that it is required). 3) Patients with high-risk leukemias with a high relapse probability will receive an additional chemotherapy agent prior to transplant using etoposide (VP16) 60mg/kg to improve the chance of remaining in remission.