This work was supported by the Mobile Telecommunications and Health Research Programme (Grant number RUM6). The Institute of Cancer Research and The Royal Marsden Hospital acknowledge funding from the Department of Health to the National Institute for Health Research Biomedical Research Centre. We thank Alison Butlin, Margo Pelerin, Alison Hart, Caroline Parsley and Karen Sampson for their work on data collection, and Deborah Hogben, Robert McCann and Ha Nguyen for their work on data management. We thank Dr Minouk Schoemaker, Dr Michael Jones, Prof. Mel Greaves and Prof. David Linch for their advice. We acknowledge the value of the Interphone study in giving a model for some aspects of data collection. We are grateful for the help of Barry Plewa and the Thames Cancer Registry, and the following consultants and their teams: Professor A Lister, Professor JG Gribben, Professor A Rohatiner, Dr J Cavenagh, Dr H Oakervee, Dr JAL Amess (St Bartholomew's Hospital), Professor G Morgan, Professor R Powles, Dr C Dearden, Dr J Treleaven, Dr M Ethell (Royal Marsden Hospital, Sutton), Prof. G Mufti, Dr S Devereux, Dr A Pagliuca (King's College Hospital), Professor D Linch, Professor AH Goldstone, Dr K Patterson, Dr R Hough, Professor A Khwaja, Dr E Morris, Dr AC Nathwani, Dr K Thomson (University College Hospital), Professor J Goldman, Dr E Olivarria (Hammersmith Hospital), Professor S MacKinnon, Prof. H Grant Prentice, Dr M Potter, Dr P Kottaridis, Dr C McNamara, Dr A Mehta, Dr A Fielding (Royal Free Hospital), Dr R Carr, Dr S Schey, Dr P Fields (Guys Hospital), Dr C Pocock, Dr P Thornton, Dr K Saied, Dr F Zwaan (Kent and Canterbury Hospital), Prof. J Marsh, Dr A Gatt, Dr V Gupta, Dr F Willis, Dr C Delley, Dr R Pettengell (St George's Hospital), Dr M Aldouri, Dr VE Andrews, Dr AG Eden, Dr Hasey (Medway Maritime Hospital), Dr S Allard, Dr N Panoskaltis, Dr C Reid (Northwick Park Hospital), Dr L Hendry, Dr G Robbins, Dr J Shirley, Dr IDC Douglas (Royal Surrey County Hospital), Dr A Virchis, Dr S Berney (Barnet Hospital), Dr AK Lakhani, Dr C De Lord, Dr B Kessel, Dr B Vadher (Farnborough Hospital), Dr Z Abboudi, Dr M Rowley, Dr H Sykes (Kingston Hospital), Professor B Bain, Dr S Abdalla, Dr S Marks (St Mary's Hospital, Paddington), Dr G Hughes, Dr M Sekhar, Dr M Al Obaidi (West Middlesex University Hospital), Dr PC Bevan, Dr S Janes, Dr P Stross (St Richard's Hospital), Dr F Matthey, Dr S Stern (East Surrey Hospital), Dr R Ireland, Dr N Ketley (Queen Elizabeth Hospital, Woolwich), Dr J Duncan, Dr MW Kenny, Mr T Corbett (Royal Sussex County Hospital), Dr J Harrison, Dr E Gaminara (Hemel Hempstead Hospital), Dr R Jan-Mohamed (Hillingdon Hospital), Dr C Rist, Dr A O'Driscoll, Dr AWW Roques (Worthing Hospital), Dr I Grant (King George Hospital), Dr PA Gover, Dr RC Grace (Eastbourne District General Hospital), Professor G Smith, Dr P Alton (Frimley Park Hospital), Professor D Catovsky, Dr E Matutes (Royal Marsden Hospital, Fulham), Dr J Behrens, Dr J Merceica (St Helier Hospital), Dr G Abrahamson, Dr N Philpott, Dr F Brito-Babapulle (Ealing Hospital), Dr H Lumley, Dr J Maitland, Dr C Pollard, Dr K Rice (Mayday Hospital), Dr S Bowcock, Dr S Ward, Dr M Mangi (Queen Mary's Hospital), Dr N Mir, Dr L Tillyer (Lewisham Hospital), Dr DS Gillett (Pembury Hospital), Dr C Costello, Dr H Yarranton (Chelsea and Westminster Hospital), Dr G Campbell, Dr M Hamblin (Colchester General Hospital), Dr E Dimitriadou, Dr S Rassam, Dr HJH Williams (Maidstone Hospital), Dr A Laurie, Dr A Miller (St Peter's Hospital), Dr A Wood (Watford General Hospital), Dr J Luckit, Dr T Kumaran (North Middlesex Hospital), Dr CJ Tew, Dr J Hanslip (Lister Hospital), Dr D Lewis, Dr AS Hughes (Oldchurch Hospital), Dr P Cervi, Dr E Watts (Basildon Hospital), Dr J Arnold, Dr M Treacy (Chase Farm Hospital), Dr J Beard, Mr S Western-Smith (The Conquest Hospital), Dr A Brownell (Queen's Hospital, Romford), Dr J Howard, Dr S Naorose-Abidi, Dr K Ryan (Central Middlesex Hospital), Dr L Jones, Dr M Semple (Epsom General Hospital), Dr C Anderson, Dr T Yeghen (Whipps Cross Hospital), Dr A C Nandi (Crawley Hospital), Dr F Al-Refaie, Dr V Oxley (Princess Alexandra Hospital), Dr JM Voke, Dr D Harvey, Dr H Davis (Queen Elizabeth II Hospital), Dr R Gale, Dr V Rhatnayake (William Harvey Hospital), Dr M Michelagnoli (Middlesex Hospital), Dr K Said (Queen Elizabeth the Queen Mother Hospital), Dr N Parker, Dr B Davis (Whittington Hospital), Dr D MacDonald (Charing Cross Hospital), Dr K Orchard (Southampton Hospital), Dr K Ardeshna (Mount Vernon Hospital), Dr MJ Mills (Southend Hospital), Dr HK Flora and Dr DS Thompson (Luton and Dunstable Hospital).