Many past scientific revolutions started with basic research, curiosity and a moment of surprise. When Emmanuelle Charpentier and her co-workers were busy studying the defense system used by bacteria to shake off attacking viruses, they knew that this discovery was relevant way beyond bacteria. Nevertheless, they did not expect that their findings could become a game-changing tool for science and medicine so quickly. The system, called CRISPR, is a sophisticated defense mechanism. When bacteria are attacked by a virus, the system recognizes the virus’s foreign DNA and slices it into pieces, destroying the attacker’s genetic information. This is an astounding discovery, but the true breakthrough lies in its application. In our current age of genetics, biologists have been in need of more precise tools for working with DNA—and over the past years since its discovery CRISPR has proved to provide exactly that: an easy-to-use, programmable instrument which allows deleting, replacing or otherwise editing DNA with unprecedented precision. “The CRISPR revolution” as Science named it, has found its way into biotech labs all over the world, enabled new solutions and experiments and will hopefully help to find treatments against many serious illnesses. In fact, the scale of this breakthrough cannot be fully understood yet—and the same is true for its ethical consequences and the risks attached to the new possibilities. At Falling Walls, Emmanuelle outlines how basic science led to this discovery and discusses the enormous benefits the new technology can provide—if used responsibly.