Wang et al. found that inhibition of miR-221 in 5-FU resistant cells resulted in reduced cell proliferation, increased apoptosis, restored chemosensitivity, and led to inactivation of the Wnt/β-catenin pathway mediated by regulating DKK2 expression in esophageal adenocarcinoma (30). This evidence concerns the gene DKK2 and esophageal adenocarcinoma.