The present protocol is a new epidemiologic component to VHL research at NIH which will relate the expression of VHL tumors to lifestyle factors (tobacco and alcohol use; physical activity), occupational exposures, reproductive and hormonal factors, demographic factors, medication use, diet, and putative susceptibility genes. Information will be collected by telephone interview and a written, self-administered diet questionnaire. A cheek cell sample will be obtained for analyses of genetic polymorphisms. Medical records will be obtained to document events reported by the subject at interview. Primary comparisons will be between VHL patients with a particular manifestation and VHL patients who are free of that condition. Additional comparisons may be made with unaffected family members who lack a mutation in the VHL gene, as appropriate.