Flow cytometric evaluation identified a significant increase of cell-surface αVβ6 on EpCs from both CRSwNP and AERD polyps relative to CRSsNP, suggesting increased availability of activated TGF-β within or adjacent to the epithelium in nasal polyps (Supplemental Figure 4C). This evidence concerns the gene TGFB1 and chronic rhinosinusitis with nasal polyps.