Dr Claire Palles studies whole genome sequencing data and targeted analyses with the aim of discovering genetic variants that affect susceptibility to colorectal cancer and Barrett’s oesophagus. The gastrointestinal track is responsible for more cancers than any other system. A condition called Barrett's oesophagus, characterised by a change in the cells lining the oesophagus, can lead to oesophageal adenocarcinoma. Only few people with Barrett's oesophagus will go on to develop cancer, and genome sequencing studies aim to identify genetic risk factors and therefore better target high-risk patients. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/