Longitudinal studies on the TGF-β1-induced FMT potential (a key event in asthmatic subepithelial fibrosis) revealed a facilitated ability of the asthmatic HBF populations in standard ‘2D’ cultures for phenotypic shifts [23, 25, 27, 28, 30, 49], that may indicate the involvement of intrinsic properties of these cells in the regulation of FMT. Here, TGFB1 is linked to fibrosis.