1. Henry Wellcome Laboratories for Integrated Neuroscience and Endocrinology, University of Bristol, Bristol BS1 3NY, United Kingdom
2. Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense, Denmark
3. Laboratory for Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
4. University of Virginia School of Medicine, Charlottesville, Virginia 22908