1 Lung Unit, Royal Marsden Hospital, 203 Fulham Road, London, SW3 6JJ, UK.
2 Lung Unit, Royal Marsden Hospital, 203 Fulham Road, London, SW3 6JJ, UK; Institute of Cancer Research, 123 Old Brompton Road, London, SW7 3RP, UK.
3 Lung Unit, Royal Marsden Hospital, 203 Fulham Road, London, SW3 6JJ, UK; Institute of Cancer Research, 123 Old Brompton Road, London, SW7 3RP, UK. Electronic address: sanjay.popat@rmh.nhs.uk.