The obstruction of the middle meatus and sinus ostia in CRSwNP may result in tissue hypoxia and induce the expression of HIF-1α and subsequent numerous inflammatory genes including VEGFα, which is associated with angiogenesis, epithelial cell overgrowth and nasal polyposis45, 46. The gene discussed is VEGFA; the disease is chronic rhinosinusitis with nasal polyps.