The genome editing technology CRISPR has emerged as a powerful new tool that can change the way we treat disease. The challenge when altering the genetics of our cells, however, is how to do it safely, effectively, and specifically targeted to the gene, tissue and organ that needs treatment. Scientists at Tufts University and the Broad Institute of Harvard and MIT have developed unique nanoparticles comprised of lipids—fat molecules—that can package and deliver gene editing machinery specifically to the liver. In a study published today in the Proceedings of the National Academy of Sciences, they have shown that they can use the lipid nanoparticles (LNPs) to efficiently deliver the CRISPR machinery into the liver of mice, resulting in specific genome editing and the reduction of blood cholesterol levels by as much as 57%—a reduction that can last for at least several months with just one shot.