The expression levels of miR-21 and TGF-β1 mRNAs appear to be higher in CRSwNP than in CRSsNP, and researchers have reported that treatment with mir-21 inhibitor suppresses TGF-β1-induced EMT in primary human nasal epithelial cells (pHNEC) [40]. This evidence concerns the gene TGFB1 and chronic rhinosinusitis with nasal polyps.