Not as easy as it looks: Gene therapy for cystic fibrosis

The gene responsible for cystic fibrosis (CF) was first identified in 1989. Since that time, gene therapy has held the promise of a cure for cystic fibrosis; however, progress has been much slower than initially hoped. Clinical trials of gene therapy have demonstrated that the corrected CF gene can be expressed successfully in the respiratory tract of subjects with CF, but only for approximately 30 days at best, and at low levels.