3.2. Analysis of Nerve Cell-Derived Mediator VIP Protein in the Blood and mRNA Levels of Esophageal Biopsies along with the Expression of VIP Receptors VAPC1, VACP2, and CRTH2 in Normal, EoE, and Dysphagia Patients. The gene discussed is VIP; the disease is eosinophilic esophagitis.