Macrophages from GVHD mice showed that skin macrophages from GVHD mice expressed much higher levels of TNF-α and IFN-γ, and a significantly lower level of IL-10 than those of sham mice (no GVHD) (Figure 1B), suggesting that the macrophages involved in GVHD possess inflammatory properties [1]. The gene discussed is IFNG; the disease is graft versus host disease.