In order to directly test the hypothesis that IL-4Rα-independent signalling by IL-13 contributes to increased initiation of chemical colon carcinogenesis, we compared AOM-induced ACF multiplicity at 6 weeks in IL-13-null mice, as well as IL-13−/− × IL-4Rα−/− DKO animals, with IL-4Rα−/− and WT mice. The gene discussed is IL13; the disease is infectious otitis media.