Apart from nasal epithelial cells, neutrophils, endothelial cells, and eosinophils are also known to produce CXCL8/IL-8 [48], which may contribute to the inconsistent observation of CXCL8/IL-8 levels originated from mucosa tissue and merely nasal epithelial cells in CRSwNP patients. The gene discussed is CXCL8; the disease is chronic rhinosinusitis with nasal polyps.