Three immunosuppresants were, and are required, but importantly, steroids were not used. Steroids have been used in the past, but increase blood sugar levels which may be toxic to islets. This research definitely offers hope to all families of a person with type 1 diabetes, just to show that a cure is possible. As can be surmised from the question on islet cell transplantation, there are not enough pancreases available to cure all of the people with type 1 diabetes. Thus, other sources of islet cells will be important.
Stem cells offer one possible source.
Stem cells are immature cells that can develop into specialized cells. Rather than discard these, they can now be used for research. It should be noted that stem cells may also be obtained from early therapeutic abortions, or possibly even from adults. At any rate, the trick will be to direct the stem cells into islets. Thus, in a developing fetus, this would be the place to look for pre-islet stem cells.