Expression of Cdx2 mRNA has been detected in esophageal epithelium in gastroesophageal reflux patients in the absence of BE [30], in the normal appearing squamous epithelium proximal to established BE [45], and can be provoked in esophageal keratinocytes in vitro when cultured under conditions of acidic or bile acid stress [6], [31]. This evidence concerns the gene CDX2 and gastroesophageal reflux disease.