A team of scientists at Whitehead Institute and the Broad Institute of MIT and Harvard have systematically evaluated the functions of more than 5,000 essential human genes using a novel, pooled, imaged-based screening method. Their analysis harnesses CRISPR/Cas9 to knock out gene activity and forms a first-of-its-kind resource for understanding and visualizing gene function in a wide range of cellular processes with both spatial and temporal resolution.