Recently, the NCI and the Universities of California, San Francisco, and Pennsylvania, completed a case-control study of cutaneous melanoma. The major risk factors for melanoma identified in the preliminary analyses were family history of melanoma and the number of dysplastic nevi. In order to further evaluate these risk factors among the cases and the controls, we have designed a second component of the investigation. The objectives of the current contract are to examine and interview the family members of individuals with familial melanoma for a linkage analysis and to examine and interview the family members of controls with dysplastic nevi for a segregation analysis. A small number of the control families may be used for linkage analysis if the segregation analysis suggests a genetic component of risk. The clinical examination and the interview are unchanged from that used in the original case-control study. This will allow the use of complex segregation and complex linkage analyses to estimate the genetic and environmental components of these risk factors.