CFTR and cystic fibrosis: As the hurdles to the success of non-viral strategies are poor transfection efficiency and transient expression, the UK CFGTC has since pursued a phase I/IIa lentiviral vector gene therapy trial for CF (Alton et al., 2017) with rSIV.F/HN-hCEF-CFTR (Mitomo et al., 2010; Griesenbach et al., 2012).