Wen et al. reported that only two T-cell phenotypes, regulatory T cells and CD4+ effector Th2-like cells, were enriched in the esophageal tissues of patients with EoE compared to controls and that the gene for the eosinophil stimulatory cytokine IL-5 was upregulated 1500-fold [5]. The gene discussed is CD4; the disease is eosinophilic esophagitis.