In eosinophilic esophagitis (EoE), bursts of refluxed acid flip open epithelial TRPV1 proton sensors, launching an ATP-fuelled NF-κB loop that up-regulates eotaxin-3, weakens tight junctions and locks in eosinophil-driven type-2 inflammation [65]. This evidence concerns the gene CCL26 and eosinophilic esophagitis.