1. From the Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio (Bu, Koo)
2. the Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, Ohio (Bu, Koo)
3. Bu is currently at the Department of Pathology and Laboratory Medicine, Children's Minnesota, Minneapolis
4. Koo is currently at the Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee