Researchers in the Liu group have developed a new genome-editing capability, called "base editing" that can alter individual DNA letters without making a double-stranded break in the genome. As a result, base editing minimizes the random insertion and deletion of bases in the gene of interest that are a common outcome of current genome editing tools including CRISPR-Cas9. Base editors allow researchers to make a C to T, or a G to A, change in a target base specified by the researcher. The Liu group researchers used base editing to correct Alzheimer’s disease-related mutations in mouse neurons with much higher efficiency and without a large number of random insertions and deletions compared with conventional CRISPR-Cas9 methods. The work is reported in Nature.