1. Kennedy Institute of Rheumatology, Imperial College School of Medicine, Hammersmith, London W6 8LH, United Kingdom 1 ;
2. UCSF Cancer Center, San Francisco, California 94143-0218 2 ; and
3. Department of Molecular Genetics and Microbiology, Robert Wood Johnson Medical School, University of Medicine and Dentistry—New Jersey, Piscataway, 08854 3 New Jersey