Moreover, Nicholas et al. [53] demonstrated that the decrease of expression levels of TGF-β1 may be associated to the edema formation in CRSwNP, whereas increase of expression levels of TGF-β1 may play a critical role in the excessive tissue repair and fibrosis formation in CRSsNP. Here, TGFB1 is linked to chronic rhinosinusitis without nasal polyps.