1. Arthritis and Tissue Degeneration Program, Hospital for Special Surgery at Weill Medical College of Cornell University, 535 E 70th Street, New York, NY 10021, U.S.A.
2. Memorial Sloan-Kettering Cancer Center, New York, NY 10065, U.S.A.
3. Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
4. Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
5. Center for Proteomic Chemistry, Novartis Institutes for Biomedical Research, CH-4002 Basel, Switzerland