IL4 and asthma: CRSwNP and asthma share similar pathophysiology and are associated with eosinophilic infiltration and Th2 cytokines such as interleukin-4, interleukin-5, and interleukin-13 (IL-4, IL-5, and IL-13) as well as high levels of local immunoglobulin-E (IgE) [8].