Scientists Don't Agree On What A Stem Cell Is

Ed. Note: The following is a press release from Mary Ann Liebert, Inc.

Jan. 4, 2005--Seeking to establish a scientific consensus on how to define a stem cell, the Editorial Board of Stem Cells and Development, a peer-reviewed journal published by Mary Ann Liebert, Inc. (, gathered opinions and viewpoints from a panel of prominent scientists and published their comments and conclusions in a paper entitled "Stem Cells: Shibboleths of Development," in the December 2004 issue (Volume 13, Number 6). The paper is available free online at

When is a stem cell truly a stem cell, and when is it not? And how do scientists from diverse disciplines differ in their views and definitions of a stem cell? Graham C. Parker, Ph.D., an Associate Editor of the Journal and Assistant Professor at the Children's Research Center of Michigan, in Detroit, writing on behalf of the Editorial Board of Stem Cells and Development, polled a group of the Journal's senior Editorial Board members and other renowned scientists in an attempt to formulate a consensus definition of a stem cell. Admittedly, he was unable to do so, concluding that, "there appears to be little to no to the properties that are either necessary, or indeed sufficient, for a cell to be termed a stem cell."

While almost all agreed that the capacity to produce multipotent, differentiated cells to support homeostasis and repair throughout the life of an organism is an essential property of a stem cell, others did not. Furthermore, many of the scientists stressed that the capacity to self-renew--to divide into an identical daughter stem cell and a more differentiated progenitor cell--is an essential characteristic of a stem cell. This characteristic maintains the stem cell pool while providing differentiated cells and is a concept derived from classic studies of the hematopoietic stem cell that has for years been accepted by most investigators. However, many readers and editors of Stem Cells and Development now take a different view in light of recent findings showing basic differences between tissue stem cells and hematopoietic stem cells. Thus, the journal re-opened the question of the definition of a stem cell. The debate shall continue; future issues will offer divergent views and commentary in the unique section of the journal, "Issues in Development." Dr. Parker shall continue to collate input as he tries to build a consensus. The first goal will be to define the minimal essential characteristics a cell must possess to be considered a stem cell.

Participating in the published debate were Dr. Edward F. Srour, Dr. Hal E. Broxmeyer, and Dr. Mervin C. Yoder, all of Indiana University School of Medicine in Indianapolis, Dr. Ursula M. Gehling of the Transplant Center at the University Hospital of Hamburg-Eppendorf, Dr. Leonard M. Eisenberg of the Medical University of South Carolina, Dr. Marlene Anastassova-Kristeva of the Bulgarian Academy of Sciences, Dr. Ralf Huss of the Institute of Pathology in Munich, Dr. Mahendra Rao of the National Institute on Aging, Dr. William H. Dodge of MPrint, LLC, Dr. Louis M. Guenin of Harvard Medical School, and Dr. Nicanor I. Moldovan of the Ohio State University in Columbus.

Stem Cells and Development is an authoritative peer-reviewed journal published bimonthly in print and online. The Journal is dedicated to communication and objective analysis of developments in the biology, characteristics, and therapeutic utility of stem cells, especially those of the hematopoietic system. A complete table of contents and free sample issue may be viewed online at

Mary Ann Liebert, Inc., is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research, including Cloning and Stem Cells, Human Gene Therapy, and Tissue Engineering. Its biotechnology trade magazine, Genetic Engineering News (GEN), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 60 journals, books, and newsmagazines is available at