IL4 and chronic rhinosinusitis with nasal polyps: Moreover, ILC2 and Th2 cells, alongside mast cells, basophils, and eosinophils, are significant sources of other inflammatory agents, including IL-4, IL-13, IL-5, prostaglandin D2, and cysteinyl leukotrienes, which further contribute to the inflammatory milieu in CRSwNP.