Two new papers in Science this week show that #CRISPR cytidine base editors causes substantial genome-wide off-target mutations in mouse embryos http://science.sciencemag.org/content/early/2019/02/27/science.aav9973 … in rice http://science.sciencemag.org/content/early/2019/02/27/science.aaw7166 … https://www.sciencemag.org/news/2019/02/crispr-offshoot-still-makes-mistakes-editing-dna-raising-concerns-about-its-medical-use …