In a recent study [23], a mouse model of OM was created using Tlr2tm1Kir (TLR2−/−) mice, lacking the Tlr2 (Toll-like receptor 2) gene, inoculated in the middle ear (ME) with streptococcal pneumonia peptidoglycan polysaccharide (PGPS). This evidence concerns the gene TLR2 and streptococcal pneumonia.