Stem Cell Glossary & Terminology
Search and understand key terms used in stem cell research.
Urine-derived stem cells
Urine-derived stem cells are a rare population of self-renewing cells found in urine that were first systematically isolated and characterized by researchers including Dr. Yun Zhao’s group in China in the early 2010s, building on much earlier observations by Sutherland and Bain, who reported exfoliated cells in the urine of newborns as far back as 1972.
Learn More: Urine-Derived Stem Cells – What They Are and What They Can Actually DoAdult (or Somatic) Stem Cell
An undifferentiated cell found in a differentiated tissue that can renew itself and differentiate (with certain limitations) to give rise to all the specialized cell types of the tissue from which it originated. It is important to note that scientists do not agree about whether or not adult stem cells may give rise to cell types other than those of the tissue from which they originate.
Human embryonic stem cell (hESC)
A type of pluripotent stem cell derived from the inner cell mass (ICM) of the blastocyst.
In vitro
Latin for “in glass”; in a laboratory dish or test tube; an artificial environment.
Induced pluripotent stem cells
Adult cells reprogrammed to an embryonic stem cell–like state by being forced to express factors important for maintaining the “stemness” of embryonic stem cells (ESCs). Mouse iPSCs were first reported in 2006 (Takahashi and Yamanaka), and human iPSCs were first reported in late 2007 (Takahashi et al. and Yu et al.). Mouse iPSCs demonstrate important characteristics of pluripotent stem cells, including expressing stem cell markers, forming tumors containing cells from all three germ layers, and being able to contribute to many different tissues when injected into mouse embryos at a very early stage in development. Human iPSCs also express stem cell markers and are capable of generating cells characteristic of all three germ layers.
Inner cell mass (ICM)
The cluster of cells inside the blastocyst. These cells give rise to the embryo and ultimately the fetus. The ICM cells are used to generate embryonic stem cells.
Mesenchymal stem cells
Cells from the immature embryonic connective tissue. A number of cell types come from mesenchymal stem cells, including chondrocytes, which produce cartilage.
Neural stem cell
A stem cell found in adult neural tissue that can give rise to neurons and glial (supporting) cells. Examples of glial cells include astrocytes and oligodendrocytes.
Somatic cell
Any body cell other than gametes (egg or sperm). See also Gamete.
Somatic stem cells
Non-embryonic stem cells that are not derived from gametes (egg or sperm cells).
Stem Cells
Cells with the ability to divide for indefinite periods in culture and to give rise to specialized cells.
Stromal Cells
Non-blood cells derived from blood organs, such as bone marrow or fetal liver, which are capable of supporting growth of blood cells in vitro. Stromal cells that make the matrix within the bone marrow are also derived from mesenchymal stem cells.
Stromal Stem Cells
A mixed population of stem cells found in bone marrow that does not give rise to blood cells but instead generates bone, cartilage, fat, and fibrous connective tissue.
Umbilical Cord Blood Stem Cells
Stem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body (hematopoietic). Cord blood is currently used to treat patients who have undergone chemotherapy to destroy their bone marrow due to cancer or other blood-related disorders.
Autologous
Cells from the same patient (personalized; lower rejection risk; harder to scale)
Allogeneic
Cells from a donor (“off-the-shelf”; scalable but immune considerations)
CAR-T / CAR-NK
Immune cells engineered with chimeric antigen receptors – often oncology; some platforms use iPSC starting material
Gene-edited cell therapy
Cells modified (e.g., CRISPR) before infusion – e.g., CASGEVY for hemoglobinopathies
RPE
Retinal pigment epithelium – cell type used in some macular degeneration programs
GVHD
Graft-versus-host disease – complication after transplant; target of some MSC products