Studies of C. rodentium infection in immunodeficient mice have established that CD4+ T cells and C. rodentium-specific antibody responses are essential components of adaptive immunity for eradicating the infection [5], [6], and recent studies have revealed that TH1 and TH17 immune responses have important host defense functions during C. rodentium infection [7]–[9]. This evidence concerns the gene CD4 and infection.