IL5 and chronic rhinosinusitis with nasal polyps: In Europe and the USA, the most prevalent endotype in CRSwNP shows a type 2 inflammatory response and is characterized by high prevalence of eosinophils, mast cells, and basophils, as well as elevated type 2 cytokines (IL-4, IL-5, IL-9, IL-13, IL-25, and IL-33) and Th2 cells.