Some are calling it the greatest discovery since insulin. Other believe it's on par with the discovery of antibiotics, but regardless, it is one of the most incredible medical discoveries in our history. After 23 years of research, Harvard professor Doug Melton says scientists are "now just one step away from the finish line" — a cure for Type 1 diabetes.

Type 1 diabetes is usually diagnosed in children and young adults and is classified as an autoimmune disorder. Type 1 diabetes occurs when the body's beta cells in the pancreas do not produce enough insulin, which is the main regulator of glucose levels in the blood. Too much sugar in the blood stream can lead to organ damage over an extensive period of time.

At other times, the body will attack and destroy the beta cells. It has nothing to do with diet or lifestyle, but it can be passed genetically. It is estimated that roughly 3 million Americans have this disease, and so far the only solution is insulin injections. These injections do not cure the disease, they just keep the patient alive. However, side effects include blindness, amputations and heart attacks.

Melton's two children are a part of the 3 million Americans statistic. His son was diagnosed as a 1-year-old, and his daughter was diagnosed at age 14. So, Melton did what any parent with the capabilities would do: He decided to find a cure, one that would be permanent.

The study, published Oct. 9 in the journal Cell, details how he used human pluripotent stem cells to create glucose-responsive beta cells — hundreds of millions of them — in vitro. They secrete quantities of insulin comparable to adult beta cells and respond to multiple sequential quantities of glucose challenges in vitro. When these beta cells were injected into mice, it cured their hyperglycemia in 10 days.

One of the reasons why this study took as long as it did was because there was no specific recipe to follow in terms of making glucose-responsive cells. Essentially, the scientists had to spend years analyzing the genes of the cell and trying different combinations until they came up with something that worked.

Stem cells have the ability to become any cell, but the challenge was guiding them into becoming the type of beta cells they were looking for. However, once they found the way, the cure worked, and quickly.

"We can cure their diabetes right away — in less than 10 days," Melton told NPR. "This finding provides a kind of unprecedented cell source that could be used for cell transplantation therapy in diabetes."

There is still more work to be done, and the potential cure still has to be tested on humans, which is expected in approximately three years. Melton and the other scientists also must find a way to hide the new cells from the body's immune system. However, other scientists are already praising the study as an enormous step forward in medicine.

"It's a huge landmark paper. I would say it's bigger than the discovery of insulin," says Jose Olberholzer, a professor of bioengineering at the University of Illinois. "The discovery of insulin was important and certainly saved millions of people, but it just allowed patients to survive but not really to have a normal life. The finding of Doug Melton would really allow to offer them really something what I would call a functional cure. You know, they really wouldn't feel anymore being diabetic if they got a transplant with those kind of cells."

While it is a phenomenal discovery, there are still other conditions that have to be considered, such as the fact that this potential cure comes from stem cells. Some people find it morally problematic that these cells are derived from human embryonic stem cells because it destroys the embryos.

Yet Melton is already working on that as well. He is hoping he will be able to make the beta cells using another kind of stem cell called an induced pluripotent stem cell, which wouldn't destroy the embryos.

The cell transplantation has already begun in primates through a collaboration with a researcher in Chicago, and other labs are ready to begin trying to duplicate Melton's experiment. Scientists are also hopeful that this could lead to drugs that could be used on beta cells that have been compromised.

Ideally, the induced pluripotent stem cells will be able to transform into the glucose-responsive beta cells, and scientists will soon find a way to encapsulate the beta cells to avoid detection within the immune system.

Still, the future of this treatment is bright, and the most difficult part is over — mapping out the change from stem cell to beta cell. As Melton said, in a perfect world, this experiment will be well on its way to human trials as soon as possible, because they are tired of curing only mice.