- Allogeneic blood and marrow stem cell transplantation (SCT) can be curative for a number of hematologic malignancies. Part of the success of this approach is an allogeneic immunologic reaction that has been demonstrated to play a role in the eradication of residual malignant disease after transplant in certain cancers (the so called graft-versus-leukemia, GVL, or graft-versus-tumor, GVT, effect). Nonetheless, relapse remains the primary cause of treatment failure after allogeneic SCT.