1. 1UCL Cancer Institute, University College London, London, UK
2. 2Department of Histopathology, Royal Free London NHS Foundation Trust, London, UK
3. 3Department of Gastroenterology, Royal Free London NHS Foundation Trust, London, UK
4. 4Department of Oncology, Royal Free London NHS Foundation Trust, London, UK
5. 5Research Department of Pathology, Cancer Institute, University College London, London, UK
6. 6Department of Cellular and Molecular Pathology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, UK