We find ourselves, in the mid-2020s, at the brink of being able to change the genetic structure of DNA with accuracy. This capability brings enormous responsibility. Genetic modification began in the 1970s with plants and evolved into animals and now humans. It has the potential to advance our ability to treat and cure disease. Potential benefits of human genome editing include faster and more accurate diagnosis, more targeted treatments and prevention of genetic disorders. Somatic gene therapies can treat sickle cell disease and other monogenic conditions. The technique could also vastly improve treatment for a variety of cancers. It is also being investigated in germline and heritable human genome editing. This alters the genome of human embryos and could be passed on to subsequent generations, modifying descendants’ traits. The techniques raise both ethical and legal issues.