For patients without GVHD (both “No GVHD-external control” and “No GVHD-internal control”), the uTh1 and uTh2 were detected only in small numbers and the frequencies of uTh1 and uTh2 within total CD4+ cells were lower than 10% in most occasions (figure 1C, 1D, point 1 of figure 2B and 3B, and figure S2B). Here, CD4 is linked to graft versus host disease.