As an immunologist, Dr. James Allison's fundamental discoveries include the definition of the structure of the T cell antigen receptor, demonstration that the T cell  molecule CD28 provides costimulatory signals necessary for full T cells activation, and that the molecule CTLA-4 is an inhibitory checkpoint which inhibits activated T cells. He proposed that immune checkpoint blockade might be a powerful strategy for therapy of many cancer types, and conducted preclinical experiments showing its potential. He was involved in the development of ipilimumab, which was approved by the FDA for treatment of metastatic melanoma in 2011. His development of the concept of immune checkpoint blockade has transformed cancer therapy and saved thousands of lives.

Dr. Allison is a member of the National Academy of Sciences and the National Academy of Medicine. He has received numerous awards, including the Lifetime Achievement Award from the American Association of Immunologists, the Lloyd J. Old Award and Pezcoller Foundation-AACR International Award from the American Association for Cancer Research, the Novartis Award for Clinical Immunology, the Medal of Honor in Basic Research from the American Cancer Society, the Harvey prize in Human Health from the Israeli Insitute of Technology, the Economist Magazine Innovation Prize for Biomedicine, the Breakthrough Prize in Biosciences, the Szent-Gyorgyi Prize for Progress in Cancer Research, and Lasker-Debakey Clinical Medical Research Award, and the Wolf Prize in Medicine.