IL4 and chronic rhinosinusitis with nasal polyps: It is possible to hypothesize that, at the basis of the OD in CRSwNP and the olfactory improvement following treatment with Dupilumab, there are immunological mechanisms with direct or indirect involvement of interleukins (ILs) and, in particular, IL-4, IL-5, IL- 13, and eosin-ophiles [14].