POSTN and chronic rhinosinusitis with nasal polyps: The strongest upregulations were observed in NP tissue from CRSwNP patients in the mild stage of the disease, i.e. 1.9-fold for IL-5 and 3.0-fold for POSTN, as well as in the severe stage of the disease: 1.9 (IL-5) and 2.4-fold (POSTN).