1. University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
2. Saint Louis University School of Medicine, Saint Louis, Missouri, USA
3. Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
4. Mayo Clinic, Rochester, Minnesota
5. School of Medicine, University of Virginia, Charlottesville, Virginia, USA
6. University of Florida College of Medicine, Gainesville, Florida, USA
7. National Cancer Institute, Bethesda, Maryland, USA
8. University of California, San Diego, San Diego, California, USA