This signalling pathway mainly produces a neutrophil recruitment, and according to the study by Cheng et al. [66], NPDF, upon stimulation by TNF-α, are able to produce increased levels of IL-17A via the PI3K/Akt pathway, thus indicating that NPDF may participate in some way in the T3 inflammatory pathway by recruiting neutrophils in cases of CRSwNP without eosinophilia. This evidence concerns the gene TNF and chronic rhinosinusitis with nasal polyps.