IL17A and infection: These effects appear to be partially dependent on ISGs, even though IL-21-induced STAT3 activation could play a role in IL-17- or IL-22-mediated protection against C. rodentium. Nanostring analysis identified that the majority of genes substantially impaired (≥ 2-fold) in the whole distal colon of Il21r-/- mice as well as in CD4+ T cells isolated from those animals after infection with C. rodentium were ISGs.