1 Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, South Parks Rd, Oxford, OX1 3SY, UK.
2 Liver Immunology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
3 Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, South Parks Rd, Oxford, OX1 3SY, UK. paul.klenerman@ndm.ox.ac.uk.
4 Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford, OX3 9DU, UK. paul.klenerman@ndm.ox.ac.uk.
5 Department of Gastroenterology and Hepatology, Basel University Medical Clinic, Cantonal Hospital Baselland, Liestal, Switzerland.