Recently, a group of advanced scientists called for stopping research to create microbes of “mirror life” in the midst of fears that synthetic organizations would have an “unprecedented risk” in life on earth. Ian Sample explains Madeleine Finlay on the reason why this work was initially exciting for scientists and what risks could be. And Kate Adamala, assistant professor of genetics, cell biology and development at the University of Minnesota, describes what made her change his mind on the pursuit of her own research on the mirror cells