CXCL8 and chronic bronchitis: Neutrophilia is a key feature of chronic bronchitis and a complex network of cytokines and chemokines including IL-8 (CXCL8), CXCL1/5/7 and CCL3 are known chemotactic factors for neutrophil migration to inflammatory sites through binding to CXCR1/2 and CCR1/5 receptors [23–25].