Following the observation that GVHD-related mortality was significantly higher in Stat1–/– recipient mice than in the WT recipients, GVHD induction was accelerated considerably (MST of 13 days in the Ifngr1–/– versus undefined in the WT group, Figure 1E) in the B6.Ifngr1–/– recipients following lethal irradiation (10.75 Gy). The gene discussed is STAT1; the disease is graft versus host disease.