Cumulative incidence of nonrelapse mortality according to donor type and the occurrence of grade II-IV hyperacute GVHD. Hyperacute GVHD was associated with a higher rate of nonrelapse mortality when it occurred in patients who received a MMrel or a MUD graft (top line) but not in patients who received a Mrel graft (lower line). In the absence of hyperacute GVHD, the rate of nonrelapse mortality was similar for related and unrelated grafts (2 middle lines).