Polymorphisms in TSLP (thymic stromal lymphopoietin) and loss-of-function mutations in the epithelial differentiation gene FLG (filaggrin) have been shown to contribute to the occurrence of AD and EoE, whereas a CCL26 (eotaxin-3) polymorphism is associated with EoE and AA (14–21). This evidence concerns the gene CCL26 and eosinophilic esophagitis.