The ability to study proteins in their native cellular context is crucial to our understanding of biology. In this work, we report a technology for intracellular protein editing, drawing from split intein–mediated protein splicing, genetic code expansion,...

Alejandro Chavez, MD, PhD, and Joonwon Kim, PhD of UCSD discuss their recent *Science Advances* publication on high-throughput insertion of tags across the genome (HITAG). This cutting-edge technique enables rapid and efficient tagging of endogenous proteins, providing an invaluable tool for the large-scale interrogation of protein function. *What is HITAG?* HITAG (High-Throughput Insertion of Tags Across the Genome) is a novel method designed to facilitate the study of protein function on a large scale. By leveraging a modified Cas9-based targeted insertion strategy that relies on nonhomologous end joining (NHEJ), HITAG allows for the rapid creation of libraries of cells, each containing a different protein of interest tagged at the C-terminus. *Applications:* Using HITAG, the researchers fused mCherry to a set of 167 stress granule-associated proteins. This enabled them to elucidate the features driving a subset of proteins to accumulate strongly within these transient RNA-protein granules. *Why is HITAG Important?* Understanding the dynamic behavior and interaction partners of proteins is crucial for building an accurate working model of the cell. Protein tags, such as those created by HITAG, facilitate numerous studies, including in vivo protein localization, affinity purification, and rapid protein degradation. *Read the full article in Science Advances:* https://www.science.org/doi/10.1126/sciadv.adg8771 *Plasmid constructs available at the nonprofit repository, Addgene* https://www.addgene.org/browse/article/28238585/ *Learn more about the Chavez Lab and research interests:* https://chavezlab.com/ Discover more about the *NHGRI Opportunity Funds* and the research supported through the NHGRI Genome Technology Program: https://genometdcc.org/opportunity-fund-program/