Specialises in the treatment of AIDS related malignancies. He has developed one of the largest centres for the management of these tumours in Europe, receiving referrals from throughout the UK and is a key opinion leader. This service has cared for over 2,500 patients with HIV-associated cancers. His clinical research covers the epidemiology, aetiology, pathogenesis and management of these tumours. He has a laboratory programme studying the immunopathology of these tumours in collaboration with a number of basic scientists. He lectures globally and has given plenary lectures in the US, Europe, India and China.