1. Department of Veterans Affairs Medical Center and University of Pittsburgh School of Medicine Pittsburgh Pennsylvania USA
2. University of Pittsburgh School of Medicine Pittsburgh Pennsylvania USA
3. Childrenʼs National Medical Center Washington, DC USA
4. Washington University St. Louis Missouri USA
5. TRiNDS Pittsburgh Pennsylvania USA
6. Centro Clinico Nemo Hospital Milan Italy
7. Newcastle University Newcastle Upon Tyne UK
8. Hershey Medical Center Hershey Pennsylvania USA
9. University of Tennessee Memphis Tennessee USA
10. Alberta Childrenʼs Hospital Calgary Alberta Canada
11. Duke University Medical Center Durham North Carolina USA
12. Lurie Childrenʼs Hospital Chicago Illinois USA
13. University of California Davis Sacramento California USA
14. Childrenʼs Healthcare of Atlanta Atlanta Georgia USA
15. University of Florida Gainesville Florida USA
16. University of Minnesota Minneapolis Minnesota USA
17. Carolinas Medical Center Charlotte North Carolina USA
18. University of Texas Southwestern Medical Center Dallas Texas USA