In a Japanese study, the researchers classified patients with CRSwNP into eosinophilic (N = 42), neutrophilic (N = 27), and non–eosinophilic non–neutrophilic (N = 61) types and reported higher IgE values and expressions of Eotaxin, IL–17A, and CD68 in eosinophilic type, which suggest different pathophysiology between these groups (21). Here, IL17A is linked to chronic rhinosinusitis with nasal polyps.