In labs and in clinical trials, scientists are seeking ways to rewrite DNA, a building block of life. Tools such as zinc-finger nucleases (ZFNs), TAL effector nucleases (TALENs) and, more recently, CRISPR/Cas9 have the power to seek out and replace faulty DNA. The possibilities seem almost limitless: with the ability to edit DNA at will, researchers theoretically could wipe out malaria-causing mosquitos, make disease- and pest-proof crops without the need for pesticides, and cure genetic diseases, such as sickle cell anemia and cystic fibrosis. Cancer is another target, with human clinical trials using CRISPR already underway, while, in separate efforts, HIV has been reportedly eliminated in mice thanks to the tool. But scientists and ethicists alike are worried about the speed at which the gene editing field is moving — and the implications of the results. In this panel, we discussed the promises and challenges presented by gene editing for individual and public health. What scientific and ethical hurdles must be overcome before tools like CRISPR and others can move safely and more widely out of the lab and into fields, farms, and hospitals This Forum event was presented jointly with NBC News Digital on May 19, 2017, as part of The Andelot Series on Current Science Controversies. Watch the entire series at ForumHSPH.org.