Why study worms? H. Robert Horvitz, David H. Koch (1962) Professor of Biology, with several notable former trainees and fellow Nobel laureates, makes the case in a recent PNAS paper. They highlight critical discoveries—spanning normal biology, gene regulation, and diseases including cancer—as well as research tools for imaging that have emerged from studies of a microscopic roundworm, and emphasize the community spirit and resource sharing that enabled and continue to enable this work.