Expression of pro-inflammatory cytokines and chemokines, including KC, MIP2α, CXCL5 and IL-1β, was significantly lower in the colon of REGγ−/− mice than in WT mice injected with AOM (Fig. 7g), which was consistent with histological analysis (Fig. 7h). This evidence concerns the gene CXCL5 and infectious otitis media.