The promise that the demand that we have far outstrips the supply, and the stem cell-derived islets essentially address that concern, because there's a limitless supply, once we can generate them, once we can show that they're fully functional, we don't have an issue with generating more. I'm Matthias Hebrok, I'm currently a professor at the Technical University in Munich and also directing an institute at the Helmholtz Institute in Munich as well. I’ve spent most of my career working on first defining how we form our insulin-producing cells in the body, and then using that information and the pathways that we have uncovered to see if we can now use that to generate stem cell-derived beta cells and islet cells that have functional properties. We do know, certainly for type 1 diabetes, that the one cell type that is missing or is not functioning any longer is the beta cell, it’s the insulin-producing cell. We also do know, as a proof of principle, that by transplanting human islets that unfortunately come from people who have died and are being isolated from their pancreas, we can cure patients with diabetes, they become normoglycaemic. The problem with that is that we just really don't have enough of these so-called cadaveric islets for transplantation. The demand that we have far outstrips the supply, we just don't have enough of those islets. And the stem cell-derived islets essentially address that concern, because there's a limitless supply. Once we can generate them, once we can show that they're fully functional, we don't have an issue with generating more. The outcomes that we're looking for, of course, is that we find out if someone doesn't need to inject themselves with insulin any longer. This field has moved really rapidly compared to other fields. If you think about that we identified the human embryonic stem cells, that are the foundation for this technology, that was in the late 1990s. 25 or so years later, we are in clinical trials. And these clinical trials, there are still phase I and phase II although they are moving into phase III trials. Many of the patients didn't get the full dose that they would need to completely regulate the abnormal glycaemia, but some did, and they seem to be doing well in reducing the levels of insulin that they have to inject themselves with, as well as with the glycaemic control that is achieved with this treatment. This is a remarkable progress that has been achieved in the short period of time, because we can now show that they are functional. The current generation of the cells require immunosuppression, because we are putting in cells that do not belong to the recipient of the transplant. There are ways to modify the immune system. There actually are clinical trials also to go out to modify it. There are ways to encapsulate the cells. My group, as well as others around the world, are thinking about how we can optimise this to generate just localised niches in which we have immune protection. People are absolutely aware that this is one of the big issues that need to be solved, and lots of people are working on it. The issue here is that we are taking an undifferentiated stem cell and turn them into a mature cell. The concern is that some of the cells that we are producing would be harmful, either because they are now producing molecules we don't want them to produce, or because they secrete insulin under conditions where insulin should not be secreted, or because they would transform into malignant cells. We don't seem to have a lot of hypoglycaemic episodes, very few actually from the information we have. So they seem to be functioning and maintain the functionality. We also don't see that these cells turn into malignant cells. This is certainly something that needs to be kept in mind. There are a lot of quality controls that are being done to ensure that we are generating right cells, that we don't have markers coming out of cells that would be unwanted. But yes, the safety concern is something that of course still is at the forefront that needs to be considered. It's not a routine treatment right now. The clinical trials have to run its course. We have to get all the information in. It's still at this point an expensive treatment, because generating these cells takes a significant period of time. It takes a number of growth factors that are quite expensive to use. Having said this, if it gets to the point that it does what we all hope, truly restore normoglycaemia in patients with diabetes, if we can address the issue of the immune protection, then I think it can last for a significant period of time upon transplantation, I can see that the price is going to come down, and it will provide a tremendous boost to the life of those patients.