Japan approves growing human cells in animals

TOKYO - Scientists in Japan will begin trying to grow human organs in animals after receiving government permission for the first study of its kind in the country.

The cutting-edge but controversial research involves implanting modified animal embryos with human "induced pluripotent stem" - so-called iPS cells - that can be coaxed into forming the building blocks of any part of the body.

It is the first step in what researchers caution is a very long path toward a future where human organs for transplant could be grown inside animals.