IL22 and infection: To confirm that Il22−/− mice in our colony also displayed increased susceptibility to C. rodentium infection, we infected C57BL/6 Il22+/+ and Il22−/− cohoused littermate mice with C. rodentium and collected fecal samples to analyze colonization by the pathogen at Days 1, 4, 7, 10, and 12 of post-infection.