Following the rational that CD8+ T cell depletion reduces the risk of GVHD induced by DLI (62), Dodero et al. reported the results of a phase I/II trial comprising 23 patients with hematological malignancies who received escalating doses of prophylactic CD8+ T-depleted DLI (median DLI number = 2) after T cell-depleted reduced-intensity allo-HCT. The gene discussed is CD8A; the disease is graft versus host disease.