IGFBP6 and cystic fibrosis: Since previous studies demonstrated that IGFBP-6 is expressed in human bronchial epithelial cells (Sueoka et al., 2000), we employed qRT-PCR to determine the IGFBP-6 expression in non-CF (Wt-CFTR CFBE) and CF (F508del-CFTR CFBE) cells.