Your News story 'Japan ramps up patent effort to keep iPS lead' (Nature 453, 962–963; 2008) concerned research on human induced pluripotent stem (iPS) cells. For international research on these cells to progress, it is essential to have a thriving research programme on human embryonic stem (ES) cells.

However, the contribution to international research on ES cells between 1980 and 2006 by the United States and China was 20% and 20.8%, respectively, whereas Japan's was only 2.1% (see Japanese Ministry of Economy, Trade and Industry press release at, in Japanese). If the Japanese government insists on having more restrictive regulations for human ES-cell research than other countries (see Nature 438, 263; 2005), Japan is in danger of being overtaken in the field of human iPS-cell research.