Allo-BMT is an established therapy with curative intent for a variety of hematologic malignancies and non-malignant conditions [26] . Alloreactive T cells of donor origin play a criticial role in both GVHD, a major complication of allo-BMT, and graft-versustumor activity, a major contributor to the efficacy of allo-BMT as a cancer therapy. Donor-recipient antigenic disparity, donor T cells, and tissue injury resulting in inflammation due to the conditioning regimen all contribute to GVHD, which primarily affects intestines, liver, skin and thymus [27] .