Of the other 327 specimens collected from 12 patients with GVHD, there were 192 “No GVHD-internal control”, 49 acute GVHD, and 86 chronic GVHD and plasma IFN-γ was detected in 7.8%, 65.3%, and 59.3% of them respectively. Here, IFNG is linked to chronic graft versus host disease.