1. Department of Pathology and Laboratory Medicine, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA;
2. Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA;
3. Department of Medicine, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA;
4. Division of Bone Marrow Transplantation, Children’s Hospital of Philadelphia, Philadelphia, PA; and
5. Department of Dermatology and
6. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA