1. Department of Radiation Oncology, University of Pittsburgh School of Medicine, PA;
2. University of Pittsburgh Cancer Institute, PA;
3. State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Center for Stem Cell Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China;
4. Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, PA; and
5. Department of Biochemistry, St Jude Children's Research Hospital, Memphis, TN