James Allison, winner of this year's Lasker–DeBakey Clinical Medical Research Award, did seminal work that has led to checkpoint-blockade immunotherapy, arguably the most exciting advance made in cancer treatment in recent years. After mapping out the molecular mechanisms of T-cell antigen recognition, regulation, and function in the 1980s and 1990s, immunologist James P. Allison hypothesized that blocking negative immune regulators (checkpoints) would give the human immune system the power to fight cancer. His testing of this hypothesis in preclinical models led to the clinical development of a new generation of active agents for cancer treatment. In some subgroups of patients, unleashing native immune-system cells to fight cancer now provides a realistic chance of long-term remission. For this seminal work, Allison, a professor at the M.D. Anderson Cancer Center in Houston, has won . . .