TGFB1 and chronic rhinosinusitis with nasal polyps: Furthermore, CRSwNP is characterized by a low concentration of transforming growth factor-β1 (TGF-β1), a downregulation of FOXP3 (transcription factor for T regulatory cells) and on transcriptional level with an upregulation of GATA-3 and T-bet compared with control nasal mucosa [25].