Conditioning regimens Before allogeneic hematopoietic stem cell transplantation for cancer, the recipient first is given a conditioning regimen (eg, a myeloablative regimen such as cyclophosphamide 60 mg / kg IV once a day for 2 days with full-dose total body irradiation or busulfan 1 mg / kg orally 4 times a day for 4 days plus cyclophosphamide without total body irradiation) to induce remission and suppress the immune system so that the graft can be accepted.