In the context of cystic fibrosis, a pseudotyped lentivirus vector with a fusion protein (F)/hemagglutinin-neuraminidase (HN) was optimized for promoter/enhancer sequences and evaluated in mice, and human air–liquid interface (ALI) cultures in preparation for a first-in-man CF clinical trial [114]. The gene discussed is MT-RNR2; the disease is cystic fibrosis.