1. Massachusetts General Hospital; Boston
2. Cleveland Clinic Foundation; Cleveland Ohio
3. Universiteit Groningen; Groningen The Netherlands
4. University of Pennsylvania; Philadelphia
5. Boston Medical Center, Boston University; Boston Massachusetts
6. Johns Hopkins Vasculitis Center, Johns Hopkins University; Baltimore Maryland
7. Hospital for Special Surgery; New York New York
8. Duke University; Durham North Carolina
9. Mayo Clinic; Rochester Minnesota
10. Genentech; San Francisco California