 Gene therapy has long held promise to correct human diseases and defects. The discovery of clustered regularly interspaced short palindromic repeats, CISPR, and its repurposing into a potent gene editing tool has revolutionised the field of molecular biology and generated excitement for new and improved gene therapies. CRISPR-Cas9 is a simple and flexible system that has been widely used in many biological research areas, including development of model cell lines, discovering mechanisms of disease, identifying disease targets, and transcriptional modulation. However, several factors influence CISPR-Cas9 efficacy, which must be addressed before effective in vivo human gene therapy can be realised. The most difficult barrier to potential in vivo use of CISPR-Cas9 is delivery. Various cargoes and delivery vehicles have been reported for CISPR-Cas9, including physical delivery methods, viral delivery methods, and non-viral delivery methods. Technologies that appear to have promise in this field include liposomes, polyplexes, gold particles, and adeno-associated virus, AAV. The therapeutic potential of CISPR-Cas9 is vast and will only increase as the technology and its delivery improve. This article was authored by Christopher Alino, Jason C. Harper, James P. Carney, and others. We are article.tv, links in the description below.