TLR9 and periodontitis: In a mouse model of bacteria-induced periodontitis, oral treatment with the prototypical cathepsin K inhibitor, odanacatib, has been reported to decrease the number of macrophages, osteoclasts, TLR4-positive cells, TLR5-positive cells, and TLR9-positive cells in the periodontitis lesion area, as well as reduce levels of certain inflammatory mediators, such as TNFα, IL6, or IL23 (25).