IL18 and infectious otitis media: However, gene expression levels of IL-22 and IL-18, the ligand and the regulator of IL-22BP30, respectively, were not changed in either AOM-3DSS-treated GF Clec7a−/− or ApcMin/+Clec7a−/− mice from the Clec7a+/+ counterparts (Fig. 6a; Supplementary Figs. 3a and 5a, d).