In preclinical studies, Azacitidine (AzaC) treatment of allotransplanted mice mitigates deleterious GVHD while preserving beneficial GVT effect, by peripheral conversion of alloreactive effector T cells into Foxp3+ Treg and epigenetic modulation of genes downstream of Foxp3 required for the suppressor function of Treg [93]. The gene discussed is FOXP3; the disease is graft versus host disease.