Lang et al. [25] in a pilot study of 11 children with hematologic malignancies used CD3/CD19 depleted grafts following a reduced intensity conditioning (RIC) regimen consisting of fludarabine, melphalan, and thiotepa; primary engraftment rate was 91% with faster CD3+ T-cells reconstitution as compared with patients who received CD34+ and CD133+ selected grafts. This evidence concerns the gene CD19 and hematologic disorder.