The assumption that BMT relies on the myeloablative effect of high dose chemotherapy and total body irradiation (TBI), has largely restricted allogeneic bone marrow transplantation in adults to those under the age of 55 years. Toxicity related mortality increases progressively with age and although some transplant centers carry out BMT in patients up to the age of 60 years, it is generally accepted that treatment related mortality prohibits the use of allogeneic bone marrow transplantation in patients beyond the age of 55 years.