In recent years, new tools for editing human DNA have allowed scientists to easily delete, change, or insert genes. One much-*hyped gene editing technique is called Crispr-Cas9. It is so simple and cheap to use that its usage in labs around the world has increased dramatically in the past two years, according to the Guardian. In April, a group of Chinese scientists successfully modified the *genome of human *embryos using Crispr. The embryos were non-viable, and the experiment – an attempt to eliminate a rare blood disease–failed. Still, the Chinese scientists’ experiment surprised the world and caused a lot of *ethical debate.