POSTN and chronic rhinosinusitis with nasal polyps: Moreover, if the combinatorial algorithm meet the three of the four markers, including IL–5 (<2.379), periostin (<3.889), IFN-γ (>0.316), and E/M ratio (<2.167), non-eosinophilic CRSwNP are diagnosed with a sensitivity of 84.4% and a specificity of 84.8%.