E. Donnall Thomas pioneered techniques for transplanting bone marrow, an operation used to treat patients with cancers of the blood, such as leukemia. For proving that such transplants could save the lives of dying patients, Thomas was awarded the Nobel Prize in physiology or medicine in 1990, a commendation he shared with Joseph E. Murray, another American physician working in the area of transplants.

Thomas spent most of his career at the Fred Hutchinson Cancer Research Center in Seattle, Washington, which he built into the world's leading center for bone marrow transplants. The Hutchinson Center has also become an important training site for doctors learning to perform such operations, and transplant centers around the world are staffed by physicians who studied with Thomas in Seattle.

Thomas was born on March 15, 1920, in the small town of Mart, Texas, to Edward E. Thomas, a doctor, and Angie Hill Donnall Thomas, a...