To further validate these results, we pretreated WT and Stat6−/− mice for five consecutive days with valproate (valproic acid, 200 mg/kg, daily), a well-known histone deacetylase (HDAC) inhibitor that leads also to chromatin decondensation [38, 39], and evaluated its effect on DNA damage response and IEC apoptosis upon the AOM challenge. Here, HDAC9 is linked to infectious otitis media.