The Nobel Prize in Physiology or Medicine 2025 has been awarded for discoveries that explain how the immune system attacks hostile infections, but not the body’s own cells.
The prize is shared by Japan’s Shimon Sakaguchi and US researchers Mary Brunkow and Fred Ramsdell.
They discovered “security guards” that eliminate parts of the immune system that could attack the body.
Their work is being used to develop new treatments for autoimmune diseases and cancer.
The winners share a prize fund worth 11m Swedish kronor (£870,000).
“Their discoveries have been decisive for our understanding of how the immune system functions and why we do not all develop serious autoimmune diseases,” says Olle Kämpe, chair of the Nobel Committee.
The Nobel panel added: “Their discoveries have laid the foundation for a new field of research and spurred the development of new treatments, for example for cancer and autoimmune diseases.”
