Esophageal biopsies from active EoE patients show increased IL-15 and IL-15Rα gene expression, and IL-15 expression correlates with EoE molecular score. RNA was extracted from esophageal biopsies, and subjected to quantitative RT-PCR gene expression analysis. (A) IL-15 mRNA expression, (B) IL-15Rα mRNA expression and (C) EoE molecular score from control healthy subjects (closed circles), active EoE non-treated patients (open circles), inactive EoE corticoid-responder patients (closed diamonds), and active EoE corticoid non-responder patients (open diamonds). Each symbol represents a single biopsy and mean ± 95% CI is indicated for each group. Statistical analysis: Student's t test. *p < 0.05; **p < 0.01; ***p < 0.001, ****p < 0.0001. (D) Correlation between EoE molecular score and IL-15 mRNA expression for all subjects. Each symbol represents a single biopsy.