IL4 and chronic rhinosinusitis with nasal polyps: [4–7] While the precise pathophysiology of CRSwNP has yet to be fully elucidated, eosinophilic inflammation and polyclonal activation of type 2 helper T cells have been demonstrated in CRSwNP, leading to the release of inflammatory cytokines, including interleukin 4 (IL-4), IL-5, and IL-13 [8–10].