In particular, Ifng–/–, Ifngr1–/–, and Stat1–/– mice are significantly more susceptible to experimental autoimmune encephalomyelitis (EAE) (20–22), collagen-induced arthritis (CIA) (12), and acute GVHD induction (8, 10, 23–25). The gene discussed is IFNG; the disease is graft versus host disease.