Investigators in the Surgery Branch of the National Cancer Institute are the general surgeons and general surgical consultants to the entire National Institutes of Health. In this role we see patients in primarily two capacities. Patients are seen in consultation for all general surgical and specialty problems except for the specialties of cardiac and orthopedic surgery. The Surgery Branch answers all emergency, as well as elective surgical consultations and provides 24 hour coverage for surgical emergencies that may arise in the Clinical Center Hospital. Increasing surgery in AIDS patients is being performed. The Surgery Branch also collaborates in the procurement of tissue for studies required by other investigative units. The degree of involvement of the Surgery Branch in the planning and execution of these studies is variable. The Surgery Branch often plays an instrumental role in the design of these studies while in other collaborations, the Surgical Service merely provides tissue. Approximately 40% of the clinical surgical effort of the Surgery Branch is devoted to these consultative and collaborative studies. - Human Subjects