Irving L. Weissman, M.D. is the Karel and Avice Beekhuis Professor of Cancer Biology, as well as
professor of pathology and developmental biology at Stanford University. Dr. Weissman was a member of
the founding Scientific Advisory Boards of Amgen (1981-1989), DNAX (1981-1992), and T-Cell Sciences
(1988-1992). He co-founded SyStemix in 1988, StemCells in 1996, and Celtrans in 2001. He is a Director
and Chair of their Scientific Advisory Boards. His research encompasses the phylogeny and developmental
biology of the cells that make up the blood-forming and immune systems. At SyStemix he co-discovered the
human hematopoetic stem cell and at StemCells, he co-discovered a human central nervous system stem cell.
In addition, the Weissman laboratory has pioneered the study of the genes and proteins involved in cell
adhesion events required for lymphocyte homing to lymphoid organs in vivo, either as a normal function or
as events involved in malignant leukemic metastases.
The principle achievement associated with Irving L. Weissman is the development of the approaches to and
the first prospective isolation of adult stem cells from any tissue and in any species. Using these
methods Weissman and colleagues reported the first isolation of mouse hematopoietic stem cells (HSC) in
1988 and then human HSC in 1992. Weissman and colleagues reported the first isolation of mouse
multipotent progenitor in 1994, of most mouse oligolineage lymphoid and myeloerythroid progenitors in
1997-2000, and their human counterparts in 2002. Weissman and colleagues reported the first prospective
isolation of human central nervous system stem cells in 2000. Weissman and colleagues reported the first
rescue of myeloablated patients with stage IV (metastatic) breast cancer with autologous-cancer-free HSC
in 2001; all patients showed prompt and sustained engraftment and at 4-5 years 36% of these patients are
alive without cancer recurrence. Similar results were found using purified autologous HSC in patients
with NHL and multiple myeloma. Weissman and colleagues first isolated leukemic stem cells as distinct
from preleukemic HSC nonleukemic progeny in AML-1-ETO acute leukemias in 2002, and this led Weissman and
others to identify other cancer stem cells in 2002.
Collectively, these studies opened the fields of adult stem and progenitor cell biology, pathology and
therapy. Concurrently, Weissman and colleagues opened the field of cell surface homing receptors by
their first identifying their existence, then identifying the proteins, and then the genes that encode
them; and showed their role in inflammation and metastases.
Professor Weissman is a member of the National Academy of Sciences and the American Association for the
Advancement of Science. He has received the Kaiser Award for Excellence in Preclinical Teaching, the
Pasarow Award in Cancer Research, and the Outstanding Investigator Award from the National Institutes of
Health. In the past three years, he won the de Villier’s International Achievement Award of the Leukemia
Society of America, the E. Donnall Thomas Award of the American Society of Hematology for outstanding
hematology research, the Ellen Browning Scripps Society Medal, and the Irvington Institute Immunologist
of the Year Award. In 2002 he received the California Scientist of the Year Award, the Van Bekkum Stem
Cell Award, the American Association of Cancer Institute Distinguished Scientist Award, the Basic Cell
Research Award of the American Society of Cytopathology, and was elected to the Institute of Medicine of
the National Academy of Sciences
Dr. Weissman has contributed much to science through public service. He was President of the American
Association of Immunology in 1994, served on the NAS/IOM Panel on AIDS in 1985/1986 and on the AIDS
Vaccine Research Advisory Board from 1996 to 2002. He has served on the NAS/NRC Committee on Science,
Engineering, and Public Policy since 1988, and was Chair of that Committee’s Panel on Benchmarking of
Immunology in 1997. He chaired the NAS/IOM/NAE/NRC Panel on Scientific and Medical Aspects of Human
Reproductive Cloning in 2001/2002. He is also the Chairman of the Immunology Section of the NAS.
