University Health Network (UHN) is a medical centre that comprises four hospitals In total, the organization devotes C$150 million a year to research and trains more than 3000 undergraduate, graduate and medical students at its member hospitals and institutes. Physicians, scientists and researchers at the organization collaborate extensively with the University of Toronto, where many of them hold professorial appointments. Princess Margaret Hospital contains the largest oncology research and treatment facility in Canada. It is home to the Ontario Cancer Institute and the Princess Margaret Hospital Foundation. In 1998, the hospital relocated to a new site south of Queen's Park on University Avenue. Toronto General Hospital is the largest member hospital in the organization, located on University Avenue directly across from Princess Margaret Hospital. Its research arm is the Toronto General Research Institute. Toronto General is a major centre for cardiac care, and home to a substantial organ transplant program. Its surgeons conducted the world's first double-lung transplant in 1986.