Two researchers, the French Emmanuelle Charpentier and the American Jennifer Doudna developed, in 2012, the CRISPR-Cas9 molecular scissors: an invention that is revolutionizing genetics. This tool allows you to cut, correct and replace, with unprecedented ease, pieces of DNA from any living being, whether plant, animal or human. Will it soon be possible to put an end to the major causes of death in our modern societies such as genetic diseases, cancer or AIDS? At the same time more exciting and more frightening: will the molecular scissors be able to modify at will an individual, even all its descendants, efficiently, quickly and at a moderate cost? This biotechnology invention, the bearer of unprecedented medical and biological progress, will perhaps win the Nobel Prize for Emmanuelle Charpentier and Jennifer Doudna.