For example, FOXF1, which is expressed in the developing foregut [17], BARX1, which is expressed at the tracheoesophageal separation site and inhibits Wnt signaling [18], and FOXP1, which regulates esophageal muscle development [19], have all been associated with BE in previous GWAS studies [11]. This evidence concerns the gene FOXF1 and Barrett esophagus.