Colin J Rees1, Sara Koo2, Kofi W Oppong3. 1. Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, UK; Department of Gastroenterology, South Tyneside District Hospital, South Shields, Tyne and Wear NE34 0PL, UK. Electronic address: colin.rees@stft.nhs.uk. 2. Department of Gastroenterology, South Tyneside District Hospital, South Shields, Tyne and Wear NE34 0PL, UK. 3. Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK; Department of Gastroenterology, Freeman Hospital, Newcastle Upon Tyne, United Kingdom.