<qa>  What is the goal of the clinical pilot trial?This clinical pilot trial is intended to evaluate the feasibility, efficacy and safety of hematopoietic stem cell transplantation HSCT from Human Leukocyte Antigen HLA-mismatched related donors for children and young adults with hematologic malignancies who lack a suitably matched related or unrelated donor. The methodology will be one that has been successfully utilized in adult patients at Thomas Jefferson University. 