Luminex-based analyses of pro- and anti-inflammatory cytokines showed significantly increased levels of CXCL1, CXCL2 and G-CSF in BALF of S100A9 KO mice as compared to WT mice on days 1 and 2 after pneumococcal infection (Fig 3E–3G). This evidence concerns the gene S100A9 and pneumococcal infection.