TLR2 and infection: It is important to notice that the interpretation of the in vivo results is difficult as TLR2−/− and particularly MyD88−/− mice are more susceptible to most of the infections; therefore, comparison of haematopoiesis between control and knockout mice during infection may reflect different tissue invasion by the microorganism, and consequently, differences in secretion of cytokines involved in haematopoiesis, which in addition also involve TLR/MyD88 mediated response to the pathogen.