1. Cancer Prevention Institute of California, Fremont, California.
2. Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California.
3. Endocrine Surgery Research Program, Department of Surgery, University of Chicago, Pritzker School of Medicine, Chicago Illinois.
4. Department of Epidemiology and Biostatistics, The University of Texas Health Science Center at San Antonio, San Antonio, Texas.
5. Department of Pediatrics, University of Chicago, Chicago, Illinois.