Quantitative real-time PCR
Total RNA was extracted from frozen sinonasal mucosa by using isolation kit ((DP431; Tiangen Biotech, Beijing, China). Total RNA was reverse transcribed with the TaqMan Reverse Transcription Reagents Kit (Applied Biosystems) based on the manufacturer’s instruction. Then, quantitative real-time PCR analysis was performed on a Prism 7500 (Applied Biosystems, Foster City, California) to evaluate the expression levels of CP110, Foxj1 and Tap73. The relative fold increase of the three genes expression was calculated by using the comparative 2-∆∆Ct methods, with the housekeeping gene Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the reference.