High response rates are seen in relapsed chronic myelogenous leukemia, but results are significantly poorer in other disease states, particularly acute leukemia. Abbreviations: CR, complete response; EBMT, European Group for Blood and Marrow Transplantation. EBMT data taken from Kolb HJ, Schmid C, Barrett AJ, Schendel DJ. Graft-versus-leukemia reactions in allogeneic chimeras. Blood 2004 Feb 1;103(3):767-76. North American data taken from Collins RH Jr, Shpilberg O, Drobyski WR, et al. Donor leukocyte infusions in 140 patients with relapsed malignancy after allogeneic bone marrow transplantation. J Clin Oncol. 1997 Feb;15(2):433-44.