Moreover, although histopathological analysis of lung tissue showed diminished lung inflammation in TLR2 KO mice during the early course of infection with S. pneumoniae PLN, which is in line with a TLR2-dependent immune response, during the later phase of pneumonia lung inflammation of TLR2 KO mice was enhanced compared with WT mice, which corresponded with the higher bacterial loads. Here, TLR2 is linked to susceptibility to pneumonia measurement.