Because of Pres. GW Bush's reluctance to open up stem cell research to include human embryos, the worry in the US was that Japan would get ahead in this research. However, Japan seems to have slipped behind the competition in this crucial area. This article at the link below explains why. First, a key quote. Then see the link for the rest of the article if it interests you.
Upon first inspection, the laws that were set in the country in 2001 were fairly permissive. Researchers could use home-grown embryonic stem cell lines, or they could import them. However, there was a catch. The teams conducting such investigations needed to get approval for their studies, from both local institutions and Science Ministry commissions. This was a real stumbling block. In addition, they had to conduct their experiments in separate facilities from teams conducting work on other types of stem cells, Nature News reports.
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Also, another article at Nature News: