Fertilization experts in the U.K. have been given a green light to start modifying human embryos, an experiment which they expect will give them unique insights into the way in which an embryo transforms into a healthy baby. The work will be limited to a brief alteration, with strict prohibitions against inserting any of the modified embryos into a human. A case of gene editing in China last year raised a hue and cry about the potential for developing designer babies, leading to a number of added restrictions on the field in various countries. Story