On Apr. 14, 1948, John Roderick Heller became the fourth and longest serving director of the National Cancer Institute (NCI). At the NCI Heller replaced Dr. Leonard A. Scheele, who had been named surgeon general. Heller headed the institute for twelve years, a period in which federal financing for cancer research and treatment was greatly expanded.

Physician, medical researcher. Heller was born in Fair Play, South Carolina, on February, 27, 1905. He received a B.S. degree from Clemson College in 1925 and an M.D. from Emory University School of Medicine in Atlanta, Georgia, in 1929. He began his medical career as an intern at South Pacific Hospital in San Francisco, California (1929–30), and worked as a surgical resident at Mills Memorial Hospital in San Mateo, California, in 1930. That same year Heller entered public-health work as a clinician and administrator for the Georgia State Board of Health on a syphilis-control project conducted jointly with the U.S. Public Health Service.

On July 1, 1960, he left the United States Public Health Service, with which he had been associated since 1931, to become president and chief executive officer of the Memorial Sloan-Kettering Cancer Center, a position in which he served until illness forced his retirement in 1964. Afterward he served as a special consultant to the American Cancer Society and the National Cancer Institute regarding international cooperation in cancer research. He officially retired in 1976.