1. Ludwig Institute for Cancer Research, Faculty of Medicine, Imperial College, St Mary's Campus, Norfolk Place, London W2 1PG, UK
2. Institut für Medizinische Mikrobiologie und Hygiene, Universität Regensburg, D-93053 Regensburg, Germany
3. Department of Clinical Oncology, Sir Y.K. Pao Centre for Cancer, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region