Mary Brunkow’s story begins not with a Nobel Prize, but with a door. As an undergraduate at the University of Washington, she had been thinking about becoming a veterinarian or a doctor. She knew she wanted to do something useful in the world, something that helped people. Then she stepped into a research lab for the first time, and the door opened onto a different kind of life. Inside, a professor she admired and his team were using fruit flies to study genetics. The room had the smell of ether in the air, the hum of people working closely together, and a kind of passionate, collaborative energy that she had never encountered before. “You walked in this door and it was like entering this new world,” she later recalled. “I just loved it. There was this real love of the science.” That moment did not just introduce her to research; it gave her a sense of what science could feel like when it is done well and shared generously. She went on to earn a doctorate and build a career in research, but she never lost the memory of that first lab—the feeling that discovery is not only a matter of intellect, but also of curiosity, companionship, and joy. In December 2025, that long-ago undergraduate moment would lead, by a route no one could have predicted, to Stockholm. Mary Brunkow received her Nobel Prize from King Carl XVI Gustaf of Sweden on Dec. 10, 2025. The honor came as part of a series profiling five Seattle-area “Uncommon Thinkers,” recognized at the GeekWire Gala in partnership with Greater Seattle Partners. But for Brunkow, the prize was not a sudden detour. It was a spotlight on a patient, human road that began with a fruit fly lab and ran through years of careful, often unglamorous work.
That road took her to Seattle-area startup Darwin Molecular, where she oversaw a team studying mutant mice afflicted by severe autoimmune disease. The scientists were trying to find the gene responsible, and in doing so, they opened a window into the immune system’s T cells. Brunkow worked on other projects at Darwin as well, but after an acquisition and a merger, the company’s local research and development operation shut down. She moved on, eventually landing at the Institute for Systems Biology, or ISB. By then, her immune-system research was well in the past—or so it seemed. Then, in October 2025, came an unexpected call. She would share the Nobel Prize in Medicine with former Darwin colleague Fred Ramsdell and Osaka University’s Shimon Sakaguchi for discoveries explaining how the immune system avoids attacking the body’s own tissues. Now a distinguished investigator at ISB, Brunkow was stunned by the honor. But Jim Heath, president of the institute, saw it as well deserved. “Mary brings an exceptional combination of scientific rigor, intellectual curiosity, and humility to her work,” he said. “She’s driven by fundamental questions about biology and isn’t afraid to challenge conventional thinking in pursuit of answers.” Heath also praised something less visible than a discovery: Brunkow’s effort to create a workplace as welcoming and vibrant as the one that had captivated her as a college undergraduate. “She’s a generous colleague who values collaboration and helps create an environment where other scientists can do their best work,” he said. “She’s deeply committed to creating opportunities for students who will become tomorrow’s scientists. Those qualities are every bit as important as the discoveries themselves.” In other words, the Nobel was not only about a gene. It was also about the kind of scientist—and colleague—Brunkow had chosen to be.
The gene hunt itself has the texture of a story that could only happen in real science. When Brunkow joined Darwin in 1994, the biotech company—whose backers included Microsoft co-founders Bill Gates and Paul Allen—was riding a wave of advances from the Human Genome Project, the massive effort to sequence humanity’s DNA playbook. Darwin scientists sought genes linked to disease that might point the way toward new treatments. “It wasn’t a one-drug company. It wasn’t hyper-focused on something very specific. It was trying to figure out how we can affect change in patients,” Ramsdell said at Life Science Washington’s annual conference in April. One project focused on “scurfy” mice, which carried an inherited mutation that caused devastating autoimmune disease. Researchers suspected the mutation disrupted a crucial regulator of the immune system. Darwin was not set up for mouse research, so Brunkow commandeered a janitor’s closet and began carefully breeding the mice to narrow down the area containing the mutant gene. The work was far more laborious and slow than today’s technology would allow, but it was groundbreaking for that period. It also delighted Brunkow. “It was a really exciting time,” she said. “It took a lot of problem solving and troubleshooting to get to the answer.” The scientists narrowed their search to 20 genes on the X chromosome and began painstakingly sequencing them. In the final gene, they found a tiny error—two extra DNA letters inserted into the sequence that rendered the protein useless. Working with Ramsdell and other collaborators, the researchers identified the mouse gene and showed that mutations in its human counterpart, FOXP3, cause a rare autoimmune disorder called IPEX. “It was nice to pull the story together. So we published a couple of nice papers. We filed patent inventions. We went to conferences and talked about it,” Brunkow said. “And then in 2004, the company closed down.” There is something deeply human in that sequence: the thrill of discovery, the satisfaction of publication, the pride of patents and conferences, and then the ordinary fragility of a company closing its doors. The science outlived the company, but Brunkow could not have known then how far it would travel.
She stayed friends with Ramsdell and followed developments in the field, but her own interests took her elsewhere. She was drawn less to one particular disease than to the challenge of finding a tiny genetic change that could have an enormous biological effect—and potentially point toward a treatment. Meanwhile, other researchers were building on the discoveries. Later research established the gene’s essential role in regulatory T cells, or Tregs—cells that restrain immune responses and protect the body from attacking itself. “I didn’t actually understand the extent to which our publications kind of blew open a whole new area in immunology,” Brunkow said. That work is now reaching patients. In June, the FDA approved Tregzi, a treatment incorporating regulatory T cells that helps prevent a serious complication of donor stem cell transplants in adults with blood cancers. For Brunkow, this is the quiet payoff of a career that has often moved between disciplines and institutions. Science is rarely a straight line from a single paper to a cure. It is more like a relay race, with one team’s careful finding becoming another team’s starting point. Brunkow’s early work on a mutant mouse in a janitor’s closet became part of a much larger story about immune regulation, transplantation, and the possibility of helping patients whose bodies are caught in the crossfire of their own defenses. The Nobel recognition did not create that story, but it made the public see the human chain of curiosity and persistence behind it.
At ISB, Brunkow has embraced a broader view of biology. The organization takes a holistic approach to medical research, bringing together scientists in areas including cancer, infectious diseases, and chronic illnesses. For her, it is a natural progression from studying individual genes to investigating the complex networks in which they operate. The ultimate goal is personalized medicine: understanding what pushes someone from health toward disease, detecting those changes early, and finding ways to intervene. The Nobel recognition has also given Brunkow a chance to broaden her impact beyond research—a platform to advocate for issues she cares about. That includes sustained research funding, support for women and other underrepresented groups in science, and stronger STEM education. She also wants to encourage scientists to support one another and work well together—the qualities she encountered in that UW fruit fly lab. “You’ve got to figure out how to play well with others,” Brunkow said. “It makes science more fun. It makes science move faster.” That sentence sounds simple, but it captures something essential about her career. She is not only a scientist who found an important gene; she is a scientist who understands that discovery depends on people, on mentorship, on generosity, and on the daily work of making a lab or an institute feel like a place where curiosity can breathe. The janitor’s closet, the fruit fly lab, the conference talks, the closed company, the unexpected call from Stockholm—all of it belongs to a life in science that has been shaped as much by collaboration as by individual brilliance.
What makes Brunkow’s story worth telling is not just the prize, but the way the prize illuminates a whole career of quiet persistence. She began as someone who wanted to help people and found a way to do it through genetics. She learned early that science is a social activity, even when it looks solitary. She worked in a startup, watched a company close, moved to a new institute, and kept following the questions that interested her. She did not spend her career chasing a Nobel; she spent it trying to solve problems, to understand how a tiny error in DNA could have enormous consequences, and to create opportunities for others. When the call came in October 2025, it must have felt surreal—a recognition of work that had begun decades earlier, in a closet, with mice, and with a team of people trying to find a gene. But the honor also belongs to the people around her: the collaborators who built on the findings, the colleagues who praised her generosity, the students who will benefit from her commitment to mentorship, and the patients whose lives may be changed by treatments that grew from that early research. Mary Brunkow’s Nobel is a reminder that science is not only a collection of discoveries. It is a human enterprise, carried forward by people who love the work, who play well with others, and who are willing to spend years in the messy middle of a problem before anyone knows how the story will end.
