IL2 and graft versus host disease: The concept of IL-2 therapy combined with other immunomodulators appeared to be optimistic in view of preliminary data, which revealed that therapy with RAPA and IL-2 could prevent autoimmune diabetes in NOD mice (2.88 × 103 IU/day of rhIL-2) [73] and reduce acute graft-versus-host disease (GVHD) in an major histocompatibility complex (MHC) mismatched murine model of bone marrow transplantation (5 × 104 IU/day of rhIL-2) [74].