Methods: Indomethacin-induced gastrointestinal injury was assessed in wild-type and several mutant murine lines. Leukocyte involvement was assessed by neutrophil depletion, impairment of recruitment (resulting from targeted disruption of fucosyltransferase VII [FTVII]), and the absence of mature T and B cells with the use of Rag 2−/− mice. Activation and oxygen free radicals were assessed using gp91phox−/− mice that exhibit normal leukocyte recruitment but are deficient in myeloid cell activation and oxygen free radical generation