To this end we focused on AMPs that are either only expressed in neutrophils (human neutrophil peptides [HNP]1–3; neutrophil α -defensins) or in epithelial cells (secretory leukocyte proteinase inhibitor; SLPI), or in both cell types (LL-37 and LCN2) and compared the levels of these AMP in asthma patients and healthy controls. The gene discussed is LCN2; the disease is asthma.