1. From the Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD; Melanoma Program, Abramson Cancer Center, University of Pennsylvania School of Medicine, Philadelphia, PA; Melanoma Clinic and Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA; and Dermatology Service, Memorial Sloan-Kettering Cancer Center, New York, NY