CD34 and graft versus host disease: When added to a CD34+ TCD haploidentical HCT, a Phase 1 study in adults using prophylactic DLI at a dose of 3 × 104 T cells/kg resulted in an unacceptably high rate of acute GvHD (73), but more promising in a pilot study, Oved and colleagues demonstrated that targeted add-back to achieve a dose of 1 × 105 T cells/kg with a CD3-/CD19- TCD graft was feasible and associated with acceptable incidence of GvHD (74).