The following is an edited excerpt.

A scientist pioneering research toward generating human organs in pigs has cleared one hurdle in gaining approval to continue his research in Japan. But he is still concerned that finalizing new research guidelines will take too long, so he is considering conducting the key experiments in the United States.

Stem cell biologist Hiromitsu Nakauchi of the University of Tokyo has been pursuing the idea of implanting human pluripotent stem cells into pig embryos engineered to be incapable of developing their own pancreases. If the technique works, the stem cells will develop into human pancreases in the pig fetus.

Read the full story here: Japan to Relax Ban on Chimeric Embryo Experiments