TFF3 and gastroesophageal reflux disease: The acceptability and accuracy of the Cytosponge-TFF3 test for screening for BE has been tested in several studies, including the Barrett's Oesophagus Trial 1 (BEST1), a cohort study in patients with previous prescriptions for acid suppressants in a UK primary care setting,16 and BEST2, a case–control study in patients with GERD with or without BE in a UK hospital setting.17 It was shown to have high sensitivity (73.3% and 79.9%, respectively) and specificity (93.8% and 92.4%, respectively) for detecting BE.