1 Environmental Autoimmunity Group, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina, USA [email protected].
2 Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA.
3 Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA.