The eosinophils’ role is unquestionable, due to the production of potent pro-inflammatory mediators, such as cytokines, GM-CSF, TGF-β and TNF-α, Th2 lymphocytes and their cytokines (IL-5, IL-4, IL-13) that are main actors in coordinating adaptive immunity in the pathogenesis of EoE. The gene discussed is TGFB1; the disease is eosinophilic esophagitis.