The expansion of health biotechnology and research into new health biotechnologies raise important questions for international governance. Health biotechnologies, in particular the "engineering" of human tissue, raise new and difficult regulatory issues. This paper focuses on the issue of regulatory arbitrage in the field of embryonic stem cell research. The first part of the paper focuses on the phenomenon of regulatory arbitrage itself. What are the political and economic drivers behind the variance in national regulatory frameworks, variance that creates the incentives for regulatory arbitrage? What is the impact of international arbitrage on the regulation of research in health biotechnology? The second part of the paper evaluates potential governance options for managing regulatory arbitrage: it sets out a typology of forms of international governance and evaluates recent efforts to build or utilise existing international structures to provide elements of governance for embryonic stem cell research. Regulatory arbitrage occurs because researchers and investors are internationally mobile, able to move between countries to capture the benefits of different regulatory regimes. Regulatory regimes for embryonic stem cell research continues to diverge sharply, even amongst those countries where such research is permitted: the paper compares the regulatory regimes in China, South Korea, the UK and the US. These differences reflect tradeoffs made at the level of the state, compromises between the drive to maintain global competitiveness via investment in the "knowledge-economy", of which biotechnology is a key component, and the complex cultural politics that determine the status of the human embryo in different societies. Societies with relatively permissive regulation may try to leverage their advantage by encouraging regulatory arbitrage, as illustrated by the example of the World Stem Cell Hub. Inaugurated by the Koreans in 2005, the Hub was intended to provide an institutional framework for the international exchange of research materials: scientists from the US and Europe would send human tissue to be processed for research purposes, tissue that had been harvested in jurisdictions where such work would be illegal. However, the fate of the ill-starred Hub underscores the need for regulatory frameworks to manage globalized research: it was effectively destroyed shortly after its inauguration, brought down by revelations about unethical research (and faked results) in the Hwang group, the world-famous South Korean research group at the centre of the Hub. Despite these problems, international initiatives in stem cell research continue: for example, there is widespread interest in "outsourcing" research to China, attracted by its relatively permissive regulatory regime and pool of low-cost skilled research staff. There is, however, increased awareness of the importance of good governance to underpin international cooperative efforts and manage regulatory arbitrage. The second half of the paper focuses on international governance options, outlining a typology of potential governance structures, characterised in terms of geographic scope (global, transnational, regional) as well as organisational remit (how far does it range beyond health biotechnology) and organisational type (formal or informal, centralised or network, public or private). This typology provides the framework for an analysis of efforts to create international governance regimes for embryonic stem cell research... ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]