The economics of developing gene therapies can make it unattractive for biopharmaceutical companies to invest in bringing a gene therapy through development and to the market for ultra-rare conditions. But researchers at the National Center for Advancing Translational Sciences are working to develop a set of gene therapy vectors that can be used in multiple indications and eliminate the time and cost of preclinical development for a range of conditions through its Platform Vector Gene Therapy, or PaVe-GT program. In this fourth and final part of our gene therapy series, we spoke to P.J. Brooks, program director in the Office of Rare Diseases Research at the National Center for Advancing Translational Sciences, about the PaVe-GT program, the potential for developing a toolkit of plug-and-play vectors, and how this can alter the cost of developing gene therapies for ultra-rare and individual patients. This series is made possible through support from BioMarin, Pfizer, Retrophin, Novartis Gene Therapies (formerly AveXis), UCB Inc., Genentech, Ultragenyx, Novartis, RegenxBIO, and Sangamo Therapeutics.