A number of things may have gone wrong when researchers edited Chinese twins Lulu and Nana's genome. Either way, the failed experiment is a cautionary tale for us all.
A philosopher's take on the ethics of products that allow parents to lighten the skin colour of their unborn baby.
CRISPR harnesses the natural defence mechanisms of some bacteria to cut human DNA strands. Then the DNA strand either heals itself or we inject new DNA to mend the gap. This is gene editing.