MUC5AC and tympanosclerosis: The morphological and histological alterations found in samples obtained from mice with hearing loss were: increased amount of inflammatory cells, thickened middle ear epithelium with fibrous polyps, increased amount of mucin-secreting goblet cells, over-ossification at the round window ridge, thickened and over-calcified stapedial artery, fusion of malleus and incus, and white patches on the inside of a tympanic membrane, some of which are typical symptoms of tympanosclerosis [28].