Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi [1]received the Nobel Prize in Physiology or Medicine on Monday for their discoveries about how the immune system regulates itself. The three researchers split 11 million Swedish kroner ($1.17 million). Their work identified regulatory T cells and the FOXP3 gene that controls them. Dr. Sakaguchi spent more than a decade solving a puzzle about the thymus. He discovered that the immune system has a backup mechanism to stop harmful cells from attacking the body's own tissues. Dr. Brunkow and Dr. Ramsdell found the specific gene responsible for this process while studying mice that developed severe autoimmune disease.

More than 200 clinical trials are now underway based on their research. Cancers attract regulatory T cells to block immune attacks. Researchers are developing drugs to turn the immune system against these cancer cells. In autoimmune diseases, regulatory T cells are missing or defective. The FOXP3 gene provides a starting point for drugs that teach the immune system to stop attacking itself.



[1] https://www.npr.org/2025/10/06/g-s1-92178/medicine-nobel-prize-peripheral-immune-tolerance-brunkow-ramsdell-sakaguchi