It was shown that CD2 depletion of allografts could prevent GVHD. Alefacept was never systemically tried in GVHD but A phase II study of BTI-322, a rat monoclonal IgG2b directed against the CD2 antigen in steroid-refractory acute GVHD showed a total response rate of 55%. We showed that alefacept might have a beneficial effect in controlling steroid resistant aGVHD and chronic GVHD. It was also shown to dramatically change the nature of transfusion associated GVHD.