Three members of McGill University’s Centre of Genomics and Policy—Rosario Isasi, Erika Kleiderman, and Centre Director Bartha Maria Knoppers—have published a global survey of restrictions on modifying the human genome. The article, which appears in Science and is free to access, comes in the midst of a simmering debate about CRISPR gene editing, a powerful technique for rewriting living genomes, which has already been used at least once in (nonviable) human embryos and inspired calls for a voluntary moratorium on editing human egg, sperm, and embryonic cells.