Dr. Leonard I. Zon is a hematologist who is known for his studies of blood stem cells and cancer using the zebrafish as a model system. He found zebrafish mutants affecting the hematopoietic system. Some of the mutants represent excellent animal models of human disease. His lab found that prostaglandins stimulate blood stem cell engraftment during transplant. He went to Muhlenberg College and Jefferson Medical College. He did a residency in Internal Medicine at the New England Deaconess Hospital, and an Oncology Fellowship at Dana-Farber Cancer Institute. He did his postdoctoral work at Boston Children’s Hospital and joined the faculty in 1991. He is the Grousbeck Professor of Pediatric Medicine at Harvard Medical School, an Investigator at Howard Hughes Medical Institute, and Director of the Stem Cell Program at Boston Children’s Hospital. He is founder and former president of the International Society for Stem Cell Research and chair of the Executive Committee of the Harvard Stem Cell Institute (HSCI). In 2005, he was President of the American Society for Clinical Investigation. In 2008, Dr. Zon was elected to the American Academy of Arts & Sciences. Dr. Zon is a member of the National Academy of Medicine and the National Academy of Sciences.

Research Interests

Dr. Zon's lab focuses on blood stem cells and cancer. His lab established zebrafish as a genetic model for the study of disease and pioneered the field of developmental hematopoiesis. His work on a zebrafish blood mutant identified ferroportin, a transporter that delivers iron to red blood cells in the marrow niche. Ferroportin is the mammalian duodenal iron transporter and is mutated in hemochromatosis (the first prediction of a human disease gene from zebrafish). The lab studies the niche for zebrafish and discovered that prostaglandins stimulate production of blood stem cells in embryos and aids stem cell transplantation in fish and mice. PGE2 also increases viral transduction and is now used in many trials using blood cell transplantation for gene therapy. They showed that venous sinusoids in the niche wrap around blood stem cells to stimulate cell division. His lab showed that irradiation is a major driver for niche location of blood stem cells during evolution. The Zon lab also has created a zebrafish model of melanoma and used this to define the beginning steps of cancer formation, transcriptional and metabolic mechanisms associated with melanoma, and studies of the cancer niche.

Membership Type


Election Year


Primary Section

Section 41: Medical Genetics, Hematology, and Oncology