CFTR and cystic fibrosis: Using DNA shuffling in an in vitro model of human ciliated airway epithelium, Li et al., [66] were able to generate two AAV variants (harboring capsid components from AAV-1, AAV-6, and/or AAV-9) with improved efficiency (25% compared to the parental vectors) to deliver cystic fibrosis transmembrane conductance regulator (CFTR) gene to human ciliated airway epithelium isolated from cystic fibrosis patients.