Total RNA was extracted from nasal UT and NP tissues (A, B) and nasal epithelial cell scrapings from UT and NP tissues (C, D). Expression of GPR41 and GPR43 mRNA was analysed by RT-PCR. The expression of mRNA was normalized to the housekeeping gene β-Glucuronidase (GUSB).*P < .05, ***P < .001, ****P < .0001. (●; control UT, ■; NP tissue)