1 David Geffen School of Medicine, UCLA, Division of Rheumatology, Harbor UCLA Medical Center, 1124 West Carson Street, E4-R17A, Torrance, CA 90502, USA. Electronic address: gkarpouzas@lundquist.org.
2 Department of Rheumatic and Immunologic Diseases, Arthritis and Musculoskeletal Center, Cleveland Clinic, 9500 Euclid Avenue, Desk A50, Cleveland, OH 44195, USA. Electronic address: husnie@ccf.org.