Here, we found decreased phosphorylated SMAD2 (p-SMAD2) levels in NP tissues from patients with CRSwNP, especially in the patients with eosinophilic type, but increased p-SMAD2 levels in diseased sinus mucosa tissues from CRSsNP compared with nasal tissues from controls (Figure 5A), suggesting an overall reduced TGF-β signaling in CRSwNP, but an elevated one in CRSsNP. This evidence concerns the gene SMAD2 and chronic rhinosinusitis with nasal polyps.