Irving Weissman

Irving Weissman isolated the first hematopoietic stem cell using prospective cell surface marker purification, creating the foundational methodology subsequently applied to identify cancer stem cells in leukemia, breast, brain, and colon cancers. His discovery that CD47, the dont-eat-me signal, is universally overexpressed on cancer stem cells led to the development of anti-CD47 immunotherapy (magrolimab) now in clinical trials for multiple cancers. His work demonstrating shared self-renewal pathways between normal and cancer stem cells including Wnt, Notch, and Hedgehog established the conceptual basis for targeting cancer stem cell-specific vulnerabilities.