When Fred Ramsdell, 64, was named a Nobel Prize winner earlier this week, he was deep in the Wyoming mountains, blissfully offline and surrounded by fresh snow. The next day, as he was wrapping up a three-week backpacking trip with his wife, her phone began to light up with hundreds of messages about the good news: Ramsdell, along with Mary E. Brunkow and Shimon Sakaguchi, had won the 2025 Nobel Prize in Physiology or Medicine for their discoveries that reshaped immunology.
Ramsdell tells WIRED he was completely unaware that the Nobel Prizes were being announced, let alone that the Nobel committee was trying to get in touch with him. Sonoma Biotherapeutics, the biotechnology firm he co-founded, told reporters that Ramsdell was “was living his best life and was off the grid on a preplanned hiking trip.”
When the news finally reached him, Ramsdell says he was shocked. He knew that the work he and his colleagues did constituted a major breakthrough, but he had already received another Swedish award for it, and thus assumed a Nobel was out of the question.
Ramsdell and his other co-winners uncovered how the body’s immune system learns to spare its own tissues, a process called peripheral immune tolerance. Part of their work involved a peculiar strain of flaky-skinned mice at the Oak Ridge National Laboratory in Tennessee, descendants of a World War II–era radiation experiment.
These “scurfy” mice were born with a fatal mutation that unleashed their immune systems against their own organs. In the 1990s, Ramsdell and Brunkow, who were working at a Seattle biotech company, identified the gene responsible—a breakthrough that paved the way for today’s generation of cell therapies that target cancer as well as other diseases by retraining immune cells rather than destroying them. WIRED spoke to Ramsdell on Tuesday, soon after he was informed about his Nobel win.
This interview has been edited for clarity and length.