It was noted that while normal controls showed significantly higher TGF-β1 in epithelial cells, the location of TGF-β1 was predominately on the apical surface of the cell bound to the cilia as opposed to NLFS and COPD, which showed significantly less TGF-β1, however it was located intracellularly in the apical border of the nucleus or somewhat in the cytoplasm. Here, TGFB1 is linked to chronic obstructive pulmonary disease.