Zephyr/SPL
Gene editing of human embryos raises pressing ethical considerations.
This week, Nature publishes the results of experiments that used genome editing to modify the DNA of a human embryo. Kathy Niakan at the Francis Crick Institute in London and her colleagues have used the CRISPR–Cas9 technique to introduce mutations into a gene called OCT4, and show how the gene is required to steer cell fate as a fertilized egg starts to divide and proliferate (N. M. E. Fogarty et al. Nature http://dx.doi.org/10.1038/nature24033; 2017).