Shimon Sakaguchi Japanese immunologist Shimon Sakaguchi at a press conference after winning the 2025 Nobel Prize for Physiology or Medicine, which he shared with American biologists Mary E. Brunkow and Fred Ramsdell, October 6, 2025. His work includes the discovery of regulatory T cells and describing their role in the immune system. (more) Shimon Sakaguchi Japanese immunologist Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/biography/Shimon-Sakaguchi Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Written by Written by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... The Editors of Encyclopaedia Britannica Last Updated: Oct. 7, 2025 •Article History Table of Contents Table of Contents Ask the Chatbot Shimon Sakaguchi (born January 19, 1951, Nagahama, Japan) is a Japanese immunologist who was awarded the 2025 Nobel Prize for Physiology or Medicine for his work on the immune system. He shared the prize with American biologists Mary E. Brunkow and Fred Ramsdell. Sakaguchi received a medical degree in 1976 from Kyōto University and a doctorate from the same institution in 1982. When he received the Nobel Prize, he was a professor of immunology at...

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