1. ; Laboratory of Molecular Biology; National Institute of Mental Health; Bethesda Maryland
2. ; Division of Gastroenterology and Hepatology; University Medical Center Nijmegen; Nijmegen The Netherlands
3. ; Division of Hematology; University of Colorado Health Sciences Center; Denver Colorado
4. ; Department of Biochemistry; Vanderbilt University and the Department of Veteran's Affairs Medical Center; Nashville Tennessee
5. ; Department of Nutrition, School of Public Health and School of Medicine; University of North Carolina; Chapel Hill North Carolina
6. ; Division of Genetics, Children's Hospital, and the Department of Pediatrics; Harvard Medical School; Boston Massachusetts USA