Besides IL-13, which may promote goblet cell hyperplasia and loss of cilia in vitro25 with relevance to asthma, transforming growth factor (TGF)-β is upregulated in the bronchial epithelium and in air-liquid interface (ALI)-human bronchial epithelial cells (HEBC) from COPD patients26 and has a central role in the remodeling of the epithelium in this disease27. This evidence concerns the gene TGFB1 and asthma.