Mary Brunkow GS ’91 has been awarded the Nobel Prize in Physiology or Medicine 2025 for her “groundbreaking discoveries” in peripheral immune tolerance. The announcement came early this morning from the Nobel Assembly at Karolinska Institutet.
Brunkow shares the award with Fred Ramsdell and Shimon Sakaguchi. She is the 83rd Princeton affiliate to receive a Nobel prize. She currently works as senior program manager at the Institute Systems Biology in Seattle.
Princeton’s most recent Nobel laureates include Emeritus Professor John Hopfield (Physics, 2024), former Assistant Professor Claudia Goldin (Economics, 2023), and honorary doctorate holder Katalin Karikó (Physiology or Medicine, 2023).
Brunkow’s contribution to the award occurred in 2001 in collaboration with Ramsdell. The two explained “why a specific mouse strain was particularly vulnerable to autoimmune diseases,” according to the Nobel announcement.
Brunkow and Ramsdell found the gene Foxp3, which is involved in immune responses, in mice, and identified that mutations in the human equivalent of it can cause IPEX, an autoimmune disease.
At the time of the discovery, Brunkow and Ramsdell were working for Celltech R&D.
The laureates’ discoveries have led to the development of treatments for cancer and other autoimmune diseases, with treatments currently in clinical trials. The research also has potential implications for organ transplants.
“We are so excited and proud of Mary Brunkow,” said Dean of the Graduate School Rodney Priestley in a press release. “Mary is an inspiring example for Princeton graduate students of how their education and training can lead them to breakthroughs that transform the world.”
While at Princeton, Brunkow worked in the lab of Shirley Tilghman, then a molecular biology professor who would go on to become Princeton’s president.
The laureates will receive their award — 11 million Swedish Kroner, or around $1.2 million — on Dec. 10, alongside the other Nobel laureates this year.
The Nobel prizes in physics, chemistry, literature, and peace will all be announced this week. The Sveriges Riksbank prize in economic sciences will be announced on Monday, Oct. 13.
Victoria Davies is a head News editor for the ‘Prince.’ She is from Plymouth, England and typically covers University operations.

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