Chemokine levels in CF quarters were significantly higher than in NC quarters at 18 h post challenge for CXCL1 and from 12 to 24 h post challenge for CXCL2 and CXCL8, while CFPD quarters showed no significant difference to NC quarters at any time (Fig. 4 A). This evidence concerns the gene CXCL1 and cystic fibrosis.