Considered by many to be the father of pediatric pathology, Sidney Farber, MD (1903-1973), is also a significant figure in the history of childhood cancer. One of his most renowned contributions to pediatric medicine was his pioneering discovery of an agent that could produce remissions in acute pediatric leukemia — a deadly disease that hitherto had no hope of cure or relief. This gallery provides a brief overview of the remarkable discovery at Children's Hospital Boston that advanced the vision of an effective cancer cure from fantasy to reality, and led to development of the current mainstay of cancer treatment: chemotherapy.