SOCS1 and graft versus host disease: When the subgroup was divided according to the CMV and GVHD status, increased expression of SOCS1 is exaggerated in the absence of GVHD (CMV+/GVHD-), whereas when GVHD is accompanied by CMV reactivation (CMV+/GVHD+), the increase is reduced (Figure 2).