Therapeutic targets in GVHD. The simplified scheme shows the mode of action of multiple immunosuppressive strategies. Although calcineurin inhibitors, mTOR inhibitors, and antimetabolites are already in clinical routine practice, all other approaches are experimental and their effect has been tested mainly in preclinical models or in vitro. Selected kinases that have been subject to targeted therapy approaches in acute GVHD are shown. Blockade of the kinases ROCK-1, Aurora A, CDK2, MEK-1/2, JAK1/2, and PI3K were shown to reduce alloreactive T-cell activation. MMF, mycophenolate mofetil; mTOR, mammalian target of rapamycin, MTX, methotrexate.