POSTN and chronic rhinosinusitis with nasal polyps: The highest IL-5, POSTN, and IL-33 mRNA expressions versus controls were observed in the NP tissue derived from CRSwNP patients in mild and severe disease compared to NP tissue from moderate disease, as well as sinonasal mucosal tissue of all severities derived from both CRSnNP and CRSwNP patients, according to VAS scoring.