Kazumori et al. found that BAs activate the expression of CDX1 in immature esophageal keratinocytes and illustrated how CDX1 interacts with CDX2 and how that interaction works, stimulating the development of BE by binding directly to each other’s promoters, leading to upregulation of BE (Kazumori et al., 2009). This evidence concerns the gene CDX2 and Barrett esophagus.