IL17A and chronic rhinosinusitis with nasal polyps: Saitoh et al. and Makihara et al. found that the numbers of IL-17A positive cells positively correlated with the numbers of eosinophils, but did not correlate with the numbers of neutrophils in Japanese patients with CRSwNP (Makihara et al., 2010; Saitoh et al., 2010).