Administration of AP1903 rapidly resolves GVHD symptoms and reduces cytokine release. In Pt. 8, (A) the highest body temperature to the time of AP1903 infusion. (B) Pictures of the skin rash were taken prior to and 25 minutes after beginning the AP1903 infusion. (C) Cytokine production in plasma measured from samples collected 4 hours prior to, 2.5 hours after beginning, and 48 hours after the infusion of AP1903.