1. From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, Divisions of
2. Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania; and
3. Oncology and Cancer Research and
4. Immunology and Infectious Diseases, Children's Hospital of Philadelphia and University of Pennsylvania Medical Center, Philadelphia, Pennsylvania;
5. Department of Pathology, Penn State Hershey Medical Center, Hershey, Pennsylvania.