Portraits of the 2025 Nobel Prize in Physiology or Medicine laureates Mary E. Brunkow (L), Fred Ramsdell (C) and Shimon Sakaguchi are shown on a screen during the announcement of the prize at the Karolinska Institute in Stockholm, Sweden, on Oct. 6, 2025. Mary E. Brunkow, Fred Ramsdell, and Shimon Sakaguchi were awarded the 2025 Nobel Prize in Physiology or Medicine on Monday for their discoveries concerning peripheral immune tolerance, the Nobel Assembly at Sweden's Karolinska Institute announced. (Xinhua/Peng Ziyang)