IL17A and Cowden disease: Finally, CECs isolated from mice on day 8 of TNBS-induced colitis were transferred alone or together with recombinant IL-17A into previously untreated mice on days 1 and 4 of induction of TNBS-induced colitis to examine 1) possible roles of CECs in the pathogenesis of CD and 2) whether IL-17A can trigger anti-inflammatory mechanisms in CECs, thus blocking their pathogenic roles in vivo.