Brunkow, Ramsdell and Sakaguchi

You are back at Järntorget, where the bronze troubadour Evert Taube stands with his sheet music in front of the old bank building. In this tour the square also holds our most recent laureates: Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi, awarded the Nobel Prize in Physiology or Medicine 2025. No statue of them stands here; this is an example placement.

Their prize was awarded "for their discoveries concerning peripheral immune tolerance". Every day your immune system meets thousands of different microbes, and many of them have come to resemble your own cells. So how does it know what to attack and what to leave alone?

Many researchers believed the answer lay in the thymus, where harmful immune cells are removed. In 1995 Sakaguchi, swimming against the tide, discovered a previously unknown class of immune cells that protect the body from autoimmune disease. In 2001 Brunkow and Ramsdell found why one mouse strain was so vulnerable to autoimmune disease: a mutation in a gene they named Foxp3. Two years later Sakaguchi linked the discoveries, showing that Foxp3 governs the development of his cells, now known as regulatory T cells.

The prize announcement called them the immune system's security guards. Look around the busy square and think of them as the quiet staff who keep the peace.