Mishra et al., Rehydration rescues <i>Il22</i>^<em>-/-</em> mice from lethal <i>Citrobacter rodentium</i> infection, 2025

IL-22 is considered essential for host survival during C. rodentium infection, yet the cause of death was not well understood. Here, we show that Il22-/- mice succumb due to dehydration, and that Fluid therapy prevents mortality, revealing IL-22-independent recovery mechanisms. These findings overturn the prevailing paradigm that IL-22 is indispensable for host survival, redefining its role in mucosal immunity.