(Nature) – More than 100 clinical trials put stem cells for regenerative medicine to the test. It’s a turning point for a field beset with ethical and political controversy.

The study is one of more than 100 clinical trials exploring the potential of stem cells to replace or supplement tissues in debilitating or life-threatening diseases, including cancer, diabetes, epilepsy, heart failure and some eye diseases. It’s a different approach from the unapproved therapies peddled by many shady clinics, which use types of stem cell that do not turn into new tissue.

All the trials are small and focus mainly on safety. And there are still substantial challenges, including defining which cells will be most fit for which purposes and working out how to bypass the need for immunosuppressant drugs that stop the body from rejecting the cells but increase the risk of infections. (Read More)