CASP3 and infection: Although the caspase-3 levels in the colonic tissue from IFNγ−/− mice were slightly elevated at day 14 post infection (p < 0.01), the magnitude of the increase was less than in the wt mice (p < 0.01, Fig. 1I), and none of the other time points showed an increase, whereas all time points in the WT animals had statistically significant increases.