Marshall S. Horwitz

Marshall S. Horwitz, M.D., Ph.D., is a Professor of Pathology, Medicine, and Genome Sciences at the University of Washington School of Medicine and an Allen Distinguished Investigator. He directs the University of Washington Medical Scientist Training Program (MSTP) and leads research on hereditary bone marrow failure and malignancy through molecular genetic pathogenesis at single-cell resolution.

His educational background includes:

• Bachelor of Science in Chemistry from Revelle College, University of California, San Diego
• M.D./Ph.D. from University of Washington MSTP

Dr. Horwitz's research integrates clinical genetics with molecular techniques to investigate hereditary blood disorders. His laboratory pioneered the discovery of hereditary neutropenia linked to ELANE mutations and familial leukemia syndromes from GATA2 transcription factor defects, advancing understanding of bone marrow failure pathogenesis and single-cell developmental mechanisms with translational implications for diagnostics and therapies.

His major scientific honors include:

• Presidential Early Career Award for Scientists and Engineers (PECASE)
• NIH Director’s Pioneer Award
• Election to the American Society for Clinical Investigation (ASCI)
• Election to the Association of American Physicians (AAP)

As MSTP director, he trains future physician-scientists while maintaining active laboratory research. His early work with Lawrence Loeb developed Directed Evolution techniques and co-founded Darwin Molecular, which identified critical genes for Alzheimer's (PSEN2), premature aging (WRN), and T cell development (FOXP3). Current research continues to explore genetic drivers of hematologic malignancies.

His laboratory at the University of Washington employs cutting-edge genomic approaches to dissect molecular pathways in hereditary bone marrow failure syndromes, collaborating with clinical teams to bridge bench discoveries with patient care.