Then, to investigate the reasons for the faster immune reconstitution in the WAS group than in the CGD group, we compared the basic clinical characteristics of the two groups of children (Table 1), including the age at transplantation, graft mononuclear cell (MNC) content and CD34+ cell count, human leukocyte antigen (HLA) matching, ABO blood group, graft type, donor type, conditioning regimen, graft versus host disease (GVHD) prophylaxis regimen, and GVHD occurrence. This evidence concerns the gene CD34 and graft versus host disease.