CXCL1 and influenza: The findings that administration of CXCL1 and CXCL2 also suppressed CXCL13 expression in influenza-infected AM and that blockade of CXCR2 binding relieved the inhibitory effect of CXCL5 on the expression of CXCL13 in infected AMs (Figure 6P) suggest that activation of the CXCL1/2/5-CXCR2 pathway can impair influenza infection-induced CXCL13 expression in pulmonary macrophages.