1. From the Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, Colorado 80206; Department of Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80206; Cadus Pharmaceuticals, 1601 Pierce St., Suite 110, Lakewood, Colorado 80214; and Department of Biology, University of California San Diego, 9500 Gilm