IL7R and infection: To determine whether gut ILC2 were required for effective viral control in the intestine, we challenged Rorafl/fl x Il7ra-Cre (Rorafl/fl) mice or littermate controls (Rora+/+ and Rora+/fl) with IP MHV68 infection, as Rorafl/fl mice are known to lack ILC2 in all tissues16.