Leonetti received his Ph.D. from The Rockefeller University. As a student in Rod MacKinnon’s lab, he used X-ray crystallography and electrophysiology to study how ion channels are regulated by calcium, voltage, and pH. As a postdoctoral fellow with Jonathan Weissman at the University of California, San Francisco, he developed high-throughput CRISPR methods to precisely insert fluorescent and affinity tags into human genes. At CZ Biohub, Leonetti and his team are developing tools that make it possible to observe proteins in unperturbed living cells and to easily isolate cellular components for biochemical analysis. Their main effort is to use CRISPR genome engineering technologies to insert GFP directly into human genes to study the corresponding proteins in their native cellular context.