Embryonic or somatic stem cells are seen as promising therapeutic tools for the treatment of number of several severe human diseases such as leukemia, diabetes, Parkinson disease, multiple sclerosis and other degenerative diseases. Embryonic stem (ES) cells have been isolated from the mouse more than twenty years ago, and it is only during the last five years that human ES cells have successfully been isolated and propagated in a very limited number of laboratories mostly in United States, Australia, Israel and Sweden.