1 Division of Cancer Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Science Centre, Manchester, UK; The Christie NHS Foundation Trust, Manchester, UK. Electronic address: neil.burnet@manchester.ac.uk.
2 Oncology Centre, Addenbrooke's Hospital, Cambridge, UK.
3 Division of Cancer Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Science Centre, Manchester, UK; The Christie NHS Foundation Trust, Manchester, UK.
4 University of Cambridge Department of Oncology, Strangeways Research Laboratory, Cambridge, UK.