DESIGN: Blood samples may be collected at the initial visit, and at follow-up visits. Tumor samples may be obtained by fine needle aspirate, by removal of pleural or peritoneal fluid, by skin punch biopsy, or by excisional biopsy, providing the tumor is accessible with minimal risk to the patients. Specific risks will be described in a separate consent to be obtained at the time of the biopsy. Samples will be studied in the HIV and AIDS Malignancy Branch, CCR, NCI; laboratories in NCI-Frederick; or those of collaborating investigators.