CD4 and graft versus host disease: In conclusion, plasma IL-10 and the frequency of CD4+IFN-γ+ (Th1) cell and CD4+IL-4+ (Th2) cell within total CD4+ T cells correlate well with the activity of GVHD in the real world situation and thus can be served as good biomarkers in monitoring the clinical course and therapeutic responsiveness of GVHD.