Given that fibrosis and stricture of the esophagus is a serious complication of eosinophilic esophagitis in human patients (Dellon et al., 2014; Cheng et al., 2012; Nhu and Aceves, 2017), we investigated the degree of collagen deposition in the submucosa of esophageal tissue from wild-type and Nik−/− mice. This evidence concerns the gene MAP3K14 and eosinophilic esophagitis.