As shown in Figure 2A, we observed accelerated GVHD-induced mortality in BALB/c→(129.Stat1–/–→129.Stat1+/+) chimeric mice compared with BALB/c→ (129.Stat1+/+→Stat1+/+) chimeras (MST of 6 days vs. 11 days, log-rank P = 0.02), suggesting that the absence of STAT1 in host hematopoietic tissue was sufficient to accelerate GVHD induction. The gene discussed is STAT1; the disease is graft versus host disease.