The transplant came after about a decade of earlier studies and transplants by Wang and his team of gene-edited organs from pigs into monkeys, including a pig heart, kidney, cornea, and bone. The group also performed a skin transplant using gene-edit pig skin into a person with severe burns.

These advances have made it possible for scientists to create pigs with organs that are more compatible with human biology, thus reducing the chances of rejection. One common edit, for instance, removes a pig’s ability to produce alpha-gal, a sugar that the human body doesn’t make.