The technology for analyzing the genetic code of animals, including humans, has grown more sophisticated even as its cost has fallen dramatically. Increasingly, we can do a lot more than just gather genomic information – we can also edit it. The ability to splice characteristics into or out of genes has led to malaria-resistant mosquitoes and is being studied as a way to remove HIV from infected cells. Clinicians may also be able to tell parents much more about genetic anomalies in their children, although they won’t always understand what they mean. Where are the opportunities and risks in genetic editing?