IFNG and colitis: Furthermore, in contrast to gp130757F/F mice and evenWT mice, gene expression of iNOS and IFNγ was increased and geneexpression of IL-19 and IL-33 was abrogated in the colon ofLysMcre/STAT3flox mice with acute DSS-induced colitis.IFNγ is known to be causatively involved in acute DSS colitis, whereasthe induction of iNOS seems to act as a critical toxic effector molecule in thepathogenesis of chronic DSS-induced colitis29, 42.