Further analysis of the protein expression of MMP-7 and MMP-9, we obtained tissue homogenates from patients with CRSsNP, CRSwNP, and control subjects, ELISA showed that the protein expression of MMP-7 and MMP-9 was in line with gene expression levels (Figure 4B). The gene discussed is MMP9; the disease is chronic rhinosinusitis without nasal polyps.