CD34 and graft versus host disease: Except for blood type of donor-recipient, there were no statistically significant differences in age, sex of donor, Donor–recipient gender match, ABO mismatch, donor type, underlying disease, stem cell source, conditioning regimen, GVHD prophylaxis, engraftment times of neutrophil and platelet, input of monocytes and CD34+ cells, and Infection peri- and post-HSCT between experimental group and control group (P≥0.05).