COPENHAGEN, Denmark (AP) — A Japanese and two American scientists have been awarded the 2017 Crafoord Prize for fundamental discoveries in immune regulation.

The prize committee says Shimon Sakaguchi of Osaka University, Fred Ramsdell from the Parker Institute for Cancer Immunotherapy in San Francisco, and Alexander Rudensky of the New-York-based Memorial Sloan Kettering Cancer Center share the 6 million Swedish krona ($660,000 award.

They were cited "for their discoveries relating to regulatory T cells, which counteract harmful immune reactions in arthritis and other autoimmune diseases."

The prize is awarded in one discipline each year — this time in Polyarthritis. The Royal Swedish Academy of Sciences gives it annually to honor achievements not always covered by its more famous Nobel Prizes. It was named after Holger Crafoord, the Swede who designed the first artificial kidney.