In 1959, while working as a junior research fellow at the Lankenau Hospital's Institute for Cancer Research in Philadelphia (later merged with the American Oncology Hospital to create Fox Chase Cancer Center), Hungerford and Peter Nowell, a pathologist at the University of Pennsylvania School of Medicine, discovered what became known as the Philadelphia chromosome.
She maintains his legacy and the family's connection with Fox Chase via the David A. Hungerford Endowed Fund in Basic Chromosome Research.
He detected a tiny abnormality in the chromosomes from cultured blood cells taken from two patients with chronic myelogenous leukemia (CML).
They believed that it was possibly a translocation, meaning the missing piece was attached in a different spot on the chromosome, but they couldn't prove it using the techniques available at the time.
At the time of his retirement due to illness in 1982, David had mapped almost half of the normal human complement of chromosomes at pachytene.