As shown in Figure 3A, we detected a significantly lower diversity of both CD4+CD25+CD127low Treg and CD4+ Tcon repertoires in GVHD patients than that in HCs (CD4+CD25+CD127low Treg cells, p = 0.003; CD4+ Tcon cells, p = 0.008). This evidence concerns the gene CD4 and graft versus host disease.