Pharmacologic CXCR2 inhibition in healthy humans, using ozone- or LPS-induced inflammation models [12–15], or in patients with severe asthma [16] or cystic fibrosis (CF) [17] showed that CXCR2 inhibition is safe and decreases neutrophilic inflammation in the airways. This evidence concerns the gene CXCR2 and cystic fibrosis.