In steroid-sensitive GVHD, we observed an increase in the average CD4+CD25+CD127low Treg repertoire diversity of 152.98% (p = 0.145; CD4+ Tcon +900,31%, p = 0.277), whereas there was a drop in diversity of −58.58% in steroid-refractory GVHD (p = 0.448; CD4+ Tcon −73,78%, p = 0.057; Figure 5A). Here, CD4 is linked to graft versus host disease.