TNF and eosinophilic esophagitis: In addition, experimental studies using an esophageal epithelial cell line and primary normal fetal esophageal fibroblasts showed that epithelial cell-derived conditioned media stimulated fibroblast secretion of TNFα which in turn stimulated TGFβ secretion from epithelial cells as well as secretion of LOX, which has previously been shown to be upregulated in EoE [12] and which helps cross-link collagen molecules to form fibers [27].