IL4 and chronic rhinosinusitis with nasal polyps: Type 2 (T2) inflammation is the most common endotype in both asthma and CRSwNP Caucasian populations [9, 10], and it is characterized by the presence of Th2 and T2 innate lymphoid cells that secrete T2 cytokines (IL-4, IL-5, and IL-13), eosinophilia, and high IgE titers [11].