 The inflammations in KO mice were associated with shortening of colon length, reduced cecum length, decreased crypt heights, and increased severity toward dextran sulfate sodium-induced colitis.In differentiated human colonic epithelial cells, Jak3 redistributed to basolateral surfaces and interacted with adherens junction (AJ) protein β-catenin.Jak3 expression in these cells was essential for AJ localization of β-catenin and maintenance of epithelial barrier functions.