IFNG and bile reflux: Proinflammatory cytokines including IFN-γ, IL-1β, IL-6, and IL-8, are expressed by epithelial cells in response to acid and bile reflux and drive the influx of a variety of proinflammatory cells including neutrophils, eosinophils, mast cells, macrophages as well as the adaptive immunity T and B cells [29, 30].