Since the level of barrier disruption and IL-22 differentiates infection with CRWT and CRM12, we investigated infection outcomes in C57BL/6 Il22-/-mice, which have impaired barrier repair mechanisms and succumb to CRWT infection.13,14 Importantly, Il22-/- mice survive infection with a CR strain lacking EspF, which does not disrupt the epithelial barrier.13 We therefore investigated how the barrier disruption caused by CRM12 impacts disease progression in Il22-/- mice. This evidence concerns the gene IL22 and infection.