https://www.sciencedaily.com/releases/2019/10/191021124511.htm

The system, called "prime editing," is capable of directly editing human cells in a precise, efficient, and highly versatile fashion. The approach expands the scope of gene editing for biological and therapeutics research, and has the potential to correct up to 89 percent of known disease-causing genetic variations.

"A major aspiration in the molecular life sciences is the ability to precisely make any change to the genome in any location. We think prime editing brings us closer to that goal," says David Liu, core institute member, Richard Merkin Professor, vice chair of the faculty, and director of the Merkin Institute of Transformative Technologies in Healthcare at the Broad Institute of MIT and Harvard. "We're not aware of another editing technology in mammalian cells that offers this level of versatility and precision with so few byproducts."