TFF3 and Barrett esophagus: Around one-in-seven of the tests (13.6%) carried out due to reflux symptoms were TFF3-positive (N = 550/4056 with known TFF3 result), indicating the presence of IM which could originate from undiagnosed Barrett’s oesophagus, focal IM at the GOJ or IM of the cardia reflecting more extensive gastric IM (Figure 2, Supplementary Table S1).