About the Authors

Sarah Walker

Affiliations Oxford Radcliffe Hospitals NHS Trust, John Radcliffe Hospital, Oxford, United Kingdom, MRC Clinical Trials Unit, London, United Kingdom

Tim E. A. Peto

Affiliation Oxford Radcliffe Hospitals NHS Trust, John Radcliffe Hospital, Oxford, United Kingdom

Lily O'Connor

Affiliation Oxford Radcliffe Hospitals NHS Trust, John Radcliffe Hospital, Oxford, United Kingdom

Derrick W. Crook

Affiliation Oxford Radcliffe Hospitals NHS Trust, John Radcliffe Hospital, Oxford, United Kingdom

David Wyllie

david.wyllie@ndcls.ox.ac.uk

Affiliation Nuffield Department of Clinical Laboratory Sciences, University of Oxford, Oxford, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SW DW. Analyzed the data: DC TP SW. Wrote the paper: SW DW. Other: Critically reviewed the manuscript: LO DC TP.