I feel nervous when there's talk about editing human DNA. Many people believe it's unethical, but a cloning expert has said that we should edit human genes to tackle genetic diseases such as cystic fibrosis.
Last month, scientists working with human embryos that couldn't develop further used a method called CRISPR to see if they could change the embryos' DNA. This was the first time a study like this had been successful. Modifying embryos outside the lab is still a long way off, but the debate is starting to heat up.