To further investigate the differences in neutrophil infiltration in TLR2−/− mice, we assessed the levels of mRNA transcript levels of keratinocyte-derived chemokine (KC) and macrophage-inflammatory protein-2 (MIP-2), (the mouse orthologs of human IL-8), and IL-17A which are the primary chemotactic signals for neutrophil infiltrates in Chlamydia and other respiratory infections in mice [9], [31]–[33]. Here, CXCL8 is linked to respiratory tract infectious disorder.