MMP-9−/− mice were used to determine a possiblecontribution of MMP-9 in the pathogenesis of C. rodentium-infection.Both wild-type (WT) and MMP-9−/− mice demonstratedhyperplastic responses to C. rodentium at 10 days post infection(PI) (Figure 2A), with the degree of hyperplasiacomparable between the two groups during this peak phase of inflammation (Figure2B) (P > 0.05). The gene discussed is MMP9; the disease is infection.