TLR5 is activated by Flagellin derived from the flagella of certain Gram-negative bacteria such as P. aeruginosa. In this respect it is noteworthy that IRAK-M−/− mice are protected from P. aeruginosa pneumonia under immunocompromised conditions caused by cecal ligation and puncture [14]. This evidence concerns the gene IRAK3 and susceptibility to pneumonia measurement.