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). This evidence concerns the gene MMP7 and chronic rhinosinusitis with nasal polyps.