1 Dermatology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
2 Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
3 Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
4 Dermatology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland. Electronic address: cowene@mail.nih.gov.