James P. Allison and Tasuku Honjo have won the 2018 Nobel Prize in Physiology or Medicine for discoveries which led to the development of cancer therapies that work by harnessing the body's own immune system.

Allison, 70, is currently chair of the department of immunology at MD Anderson Cancer Center in Houston. Honjo, 76, is a distinguished professor at the Kyoto University Institute for Advanced Study and a professor in the department of immunology and genomic medicine at Kyoto University in Japan.

Their work centers on harnessing the immune system to arrest the development of cancer. The discoveries led to one of the decade's major advance in cancer therapy — drugs called checkpoint inhibitors. Several such drugs have been approved for use in the US.

According to his website, Honjo discovered a key protein – Programmed Cell Death Protein 1 — in controlling whether cells live or die, a central process in determining whether cells become cancerous and grow into tumors or behave normally.

The Nobel committee cited Allison's study of a protein called CTLA-4 that functions as a brake on the immune system. By releasing this brake, the body's own immune system can be stimulated to attack tumors.

The prize is currently worth $1,012,297.05 and will be split between the winners.

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