Puneet and Isabel’s research has achieved a clinical milestone using CRISPR technology to transplant a genetically modified pig liver into a human. This is just the beginning though and Isabel is on the cusp of perfecting CRISPR so that it can be used to modify human genome without any adverse side effects. The consequences could be unprecedented - a cure for many genetic disorders; but also potential genome editing of our future generations without their consent. How far will Isabel go in her pursuit?