Their research has led to the development of drugs that release that Human immune system against the cancer cells.
The scientists' work in the 1990s has since swiftly led to new and dramatically improved therapies for cancers such as melanoma and lung cancer, which had previously been extremely hard to treat.
'Therapies based on his discovery proved to be strikingly effective in the fight against cancer, ' the assembly said in a statement.
Allison, a professor at the University of Texas MD Anderson Cancer Centre, studied a protein that functions as a brake on the immune system and realized the potential for unleashing immune cells to attack tumours if the brake could be released. The victor of the Nobel Peace Prize will be named Friday.
In the early 1990s, Allison had been studying a protein called CTLA-4, which sits in the outer layer - the membrane - of an active T-cell and behaves like an off-switch. The first anti-PD-1 drugs were pembrolizumab (Merck's Keytruda), and nivolumab (Bristol-Myers Sqibb's Opdivo), both initially approved in 2014 for the treatment of melanoma: Both block the PD-1 (programmed cell death 1) protein on the surface of the immune system T cells, with the result that those cells attack and, sometimes, eliminate the tumor.
Allison said scientists need to better understand "how these drugs work and how they might best be combined with other therapies to improve treatment and reduce unwanted side effects".
The 70 year-old Allison worked as a postdoctoral fellow at Scripps Research from 1974-77, when the center was known as the Scripps Clinic and Research Foundation.
"This year's #NobelPrize constitutes a landmark in our fight against cancer".
After Allison himself replicated the experiment, "that's when I said, OK, we've got something here".
"I've been doing this sort of stuff for years, and I'd never seen anything like that", Allison said.
Allison, who is the chair of Immunology and executive director of the Immunotherapy Platform, is the first MD Anderson scientist to receive the world's most coveted award for discoveries in the fields of life sciences and medicine.
The therapy "has now revolutionized cancer treatment and has fundamentally changed the way we view how cancer can be managed", the statement added. Allison's success with CTLA-4 in cancer persuaded Honjo to consider his molecule in cancer as well-and he found PD-1 therapy was even safer and more effective against a number of cancers, including lung cancer, which kills about 150,000 Americans a year. "We need more basic science research to do that".
The winners of this year's physics prize will be announced on Tuesday, followed by the chemistry prize on Wednesday.
Arnault, 72, is married to a member of the Swedish Academy which selects the Nobel Literature Prize victor, and his cultural club Forum received generous funding from the Academy.