Lower colonic apoptotic cell and T lymphocyte counts were accompanied by lower IL-6 and IFN-γ protein concentrations in ex vivo colonic biopsies obtained from gnotobiotic IL-10−/− mice six days following infection with the knockout mutant NCTC11168::cj0268c as compared to the parental strain NCTC11168 (Fig. 6A, B). The gene discussed is IFNG; the disease is infection.