CD34 and chronic graft versus host disease: In the previous retrospective analysis by the Blood and Marrow Transplant Clinical Trials Network (BMT CTN), the use of CD34-selected T cell-depleted grafts (with target graft composition of CD34+ cells > 5 × 106/kg and CD3+ cells < 1 × 105/kg) did not result in reduced relapse rates or improved RFS or OS at 2-years, but did lead to a significantly lower incidence of chronic GVHD in 44 patients when compared to an overall similar cohort of 84 patients who received T-replete PBSC allografts and pharmacologic immune suppression therapy for GVHD prophylaxis [45].