 Allogeneic bone marrow transplantation may cure or ameliorate illnesses of many types; however the toxicity of the procedure limits its broad applicability. Hematologic malignancies of all types have shown responses. Those with marrow failure, such as aplasia, and hemoglobinopathies have further shown responses in multiple trials as well. Even patients with certain solid tumors, such as breast, renal cell, and melanoma have shown partial or complete responses to allogeneic therapy. The limiting effect of the historical methods of aggressive induction for allogeneic therapy were extremely toxic, requiring limiting those offered allogeneic therapy to the healthiest of the ill patients. Work over the last decade has shown that less toxic agents targeting the immune system effectively allowed engraftment with less effects on the patients liver, lungs, and other vital organs. We and others have completed multiple trials showing the effective use of these less toxic, non-myeloablative, regimens for allogeneic therapy. Trials with fludarabine and cyclophosphamide at standard doses patients are not ablated and recover blood counts in 2 weeks allow for 80 of patients to engraft donor cells. Some groups have added low doses of radiation to this combination, with 80-100 allogeneic engraftment. The lessened toxicity of this approach has been confirmed in multiple studies, including our own data with the specific schema in this treatment plan reviewed below. Phase I results with this combination: Our group has combined the above combination of fludarabine and cyclophosphamide with the antibody CAMPATH 1H. This antibody is given to the patient to purge the immune system and prevent rejection. It also purges the T cells in the donated stem cells to minimize graft versus host disease GVHD. This approach has been proven successful in multiple trials using standard more toxic ablative procedures. Our approach over the last 3 years has been very successful using this antibody with the less toxic non-myeloablative procedure and our trials have completed. 