CLDN1 and eosinophilic esophagitis: Gastroesophageal reflux disease patients also display esophageal barrier alterations similar to EoE patients, such as dilated intercellular spaces (DISs), basal cell hyperplasia (Zentilin et al., 2005), and tight junction proteins alterations (e.g., claudin-1) (Vieth et al., 2016).