In presentation of our data in context of other clinical series, we have identified a few bone marrow transplant preparative regimens that appear to have a superior advantage over others as far as their antileukemic effects are concerned. So far, the delayed and late effects of the treatment appear to be quite acceptable considering the ultimate fatal outcome in the acute leukemias, in particular those in their second remission. GvHD and viral infections account for about two-thirds of the mortalities in series where leukemic relapse is very low. It is hoped that solutions or at least partial solutions will not only improve the overall therapeutic results, but will allow us to extend the procedure to older patients. It is suggested that the need for unrelated HLA "matched" donors may be supplanted by the use of autologous bone marrow transplants, particularly in the older patients.