Moreover, preclinical data from our group have shown that PTCy rapidly induces suppressive mechanisms within 24 h that are sufficient to prevent GVHD induction by subsequent donor T-cell infusions [15, 17], with this effect dependent on Foxp3+ Tregs. [20] Indeed, other groups have found that the risk for GVHD from DLI in PTCy-treated patients appears more modest than that seen with conventional calcineurin-inhibitor-based GVHD prophylaxis [3, 9, 12, 13, 21–24] even when using HLA-partially-mismatched donors. The gene discussed is FOXP3; the disease is graft versus host disease.