Shoukhrat Mitalipov, a reproductive biologist at Oregon Health and Science University, is nothing if not a pioneer. In 2007, his team published proof-of-principle research in primates showing it was possible to derive stem cells from cloned primate embryos. In 2013, his team was the first to create human embryonic stem cells by cloning. Now, in 2017, his team is reported to have safely and effectively modified human embryos using the gene editing technique CRISPR.