We also saw statistically significant upregulation in the level of CXCL3, a CXCL-1–type chemokine that is important for attracting neutrophils to the site of infection, in the lungs of mice infected with 107 CFU of the cda1Δ2Δ3Δ mutant (Fig. 2B). This evidence concerns the gene CXCL3 and infection.