POSTN and chronic rhinosinusitis without nasal polyps: Gene expression of collagen I, collagen III, vimentin, periostin, tenascin C was significantly higher in CRSsNP compared to CRSwNP group, accordingly collagen I −4.764 ± 2.422 vs. −2.588 ± 4.129 ΔΔCT over the control group, p = 0.0295; collagen III −7.388 ± 2.994 vs. −3.313 ± 4.942 ΔΔCT over the control group, p = 0.0209; vimentin −5.806 ± 1.162 vs. −2.852 ± 2.828 ΔΔCT over the control group, p = 0.0064; periostin −11.222 ± 2.252 vs. −4.788 ± 5.533 ΔΔCT over the control group, p = 0.0020; tenascin C −5.982 ± 1.777 vs. −2.690 ± 3.234 ΔΔCT over control group, p = 0.0049.