It is conceivable that, at the basis of the OI in CRSwNP and of the olfactory recovery following treatment with Dupilumab, there are immunological mechanisms with the direct or indirect involvement of interleukins (ILs) and in particular IL-4, IL-5, IL-13, and eosinophils [20]. The gene discussed is IL4; the disease is chronic rhinosinusitis with nasal polyps.