Journalists watch a screen displaying the field of science of the award winners during a press conference to announce the winners of the 2025 Nobel Prize in Physiology or Medicine at the Karolinska Institute in Stockholm, Sweden, on October 6, 2025. Mary E. Brunkow and Fred Ramsdell of the United States and Japan's Shimon Sakaguchi won the Nobel Prize in Medicine on Monday for research into how the immune system is kept in check, the Nobel jury said. (Photo by Jonathan Nackstrand / AFP) (Photo by JONATHAN NACKSTRAND/AFP via Getty Images)