Twenty-four hours post infection myeloperoxidase (MPO) and neutrophil elastase (NE) levels were found to be significantly higher and increased numbers of neutrophils were observed by immuno-histochemistry in the lungs of clodronate treated mice as compared to those receiving control liposomes (Fig. 1B,C, Supplemental Fig. 3A–C)). This evidence concerns the gene MPO and infection.