CXCL8 and asthma: However, in one bronchial biopsy study of severe asthma exacerbations, there was a similar increase in the number of mucosal eosinophils and neutrophils that was accompanied by increased expression of mRNA for the chemokines CXCL5 (epithelial cell-derived neutrophil-activating peptide-78) and CXCL8 (IL8) and their receptors CXCR1 and CXCR2, but the mechanisms involved are unknown [9].