In a study that measured TLR3 expression in the skin of patients with acquired cholesteatoma and those with a normal external auditory canal, TLR3 expression was weak in normal skin but was clearly detected in the skin of cholesteatoma patients, where it was mainly observed in the matrix (layer of keratinizing epithelium) and perimatrix (granulation tissue) [36]. This evidence concerns the gene TLR3 and cholesteatoma.