Mary E. Brunkow

Mary E. Brunkow (born 1961) is an American biologist who was awarded the 2025 Nobel Prize for Physiology or Medicine for her work on the immune system. She shared the prize with American biologist Fred Ramsdell and Japanese immunologist Shimon Sakaguchi.

Brunkow received a doctorate in molecular biology from Princeton University in 1991. When she received the Nobel Prize, she was a senior program manager at the Institute for Systems Biology in Seattle.

In the 1990s Brunkow and Ramsdell worked at Celltech Chiroscience, a company that was developing drugs for autoimmune diseases, in which the immune system fights against the body’s own cells. They were studying a variety of mice, called scurfy, that had such a disease. They identified the gene responsible for the disease and found that the same gene in humans was responsible for an autoimmune disease. Sakaguchi and others discovered that the gene was responsible for the development of regulatory T cells, which control the body’s immune reactions by stopping other T cells from attacking normal cells.