Making stem cells count for global health.

Developing countries such as China, India and Brazil are making large investments in the stem cell field. Here we argue that hands-on involvement in the field by these countries is essential if the products developed are going to be locally relevant, affordable and appropriate. However, stem cells are a high-risk investment and any global health impacts are still likely to be far off. Even if they are eventually successful, better clinical oversight and measures to ensure access are required for stem cells to have a substantial and equitable impact.