Researchers and commentators reported new advances in delivering genome editors directly to tissues in living organisms. Doudna and colleagues framed a rational design approach for targeted delivery systems in Nature Biotechnology, while an independent review highlighted recent technical progress enabling more specific in vivo delivery of CRISPR and related editors. Both pieces stress improvements in tropism, carrier chemistry and targeting strategies that aim to reduce off-target distribution and immune responses. The reporting names academic groups and industry teams working on lipid nanoparticles, viral vectors and novel ligand-directed carriers. Targeted delivery — the ability to ferry editors to specific cell types in patients — is a bottleneck for clinical translation; these studies provide design principles and case examples that developers can apply to therapeutic programs. For readers: "in vivo delivery" refers to methods used to administer gene-editing tools directly into living organisms rather than into cells ex vivo.