PTGS2 and chronic rhinosinusitis with nasal polyps: Our previous study using a PCR microarray analysis to catalog oxidative stress-related gene expression revealed that the prostaglandin-endoperoxide synthase 2 (PTGS2) gene, also commonly named cyclooxygenase-2 (COX-2) gene, out of 84 genes is significantly upregulated for 2.31 folds in NP tissues of Taiwanese patients with CRSwNP than nasal mucosa tissues of healthy controls12.