When the Nobel Assembly called Dr. Mary E. Brunkow around 1 a.m. on October 6 to deliver the news that she had been awarded the 2025 Nobel Prize for Physiology or Medicine, she did not answer the phone call. When they called immediately a second time she set her phone to “Do Not Disturb” and went back to sleep.

It wasn’t until almost 4 a.m., when her husband woke her up—and after an Associated Press photographer had shown up at their doorstep requesting a photo—that Brunkow, who works at the Institute for Systems Biology, was wise to the news that she had been awarded the Nobel Prize, the highest honor in medicine.

Brunkow (a University of Washington alumna), along with her former colleague Fred Ramsdell, and Shimon Sakaguchi at Osaka University in Japan, earned this year’s prize “for their groundbreaking discoveries concerning peripheral immune tolerance that prevents the immune system from harming the body,” according to the Nobel Assembly.

Adam Smith from the Nobel Assembly called a third time at 4:30 a.m. and finally connected with Brunkow, who was not expecting the news. The discovery for which she was recognized had long been put to bed. The paper announcing the findings was published in 2001, while she was working with Ramsdell at Darwin Technologies, a Bothell-based biotech firm no longer in business.

The scientists had discovered that scurfy mice with defective T cell tolerance have a mutation in a gene that they dubbed Foxp3, and that mutations in the human equivalent of this gene cause an autoimmune disease called IPEX. The laureates’ discoveries launched the field of peripheral tolerance, spurring the development of medical treatments for cancer and autoimmune diseases prevalent today. This may also lead to more successful transplantations, said the Nobel Assembly in awarding the prize.

“It was an amazing team effort back when we did the work,” Brunkow told Smith upon learning the news. “My career in science has changed quite a bit since that work wa done and I don’t actually even work in that particular field anymore, so it’s an honor to have been a part of that initial work.”