 Jak3 is also implicated in mucosal differentiation and predisposition to inflammatory bowel disease in mice model.These studies show that Jak3 is expressed in colonic mucosa of mice, and the loss of mucosal expression of Jak3 results in reduced expression of differentiation markers for the cells of both enterocytic and secretory lineages.Jak3 KO mice showed reduced expression of colonic villin, carbonic anhydrase, secretory mucin muc2, and increased basal colonic inflammation reflected by increased levels of pro-inflammatory cytokines IL-6 and IL-17A in colon along with increased colonic myeloperoxidase activity.