Researchers say CRISPR edits to a human embryo worked. But critics still doubt it
Reports that a heart disease–causing version of a gene had been corrected remain contested
![human embryos](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2018/08/081718_TS_embryo-editing_feat.jpg?fit=860%2C460&ssl=1)
ALTERED OR NOT? These human embryos were edited with CRISPR/Cas9 to repair a gene that can cause heart failure. A follow-up study claims to confirm the result, but other scientists contend the embryos might not have been fixed.
Salk Institute