Stem Cell Pathways

Stem cells are characterized by the ability to self-renew, or divide without senescing, and to differentiate into specialized somatic cells. Multiple stem cell subtypes have been identified, including embryonic, induced pluripotent, and adult stem cells. Embryonic stem cells are pluripotent and can differentiate into all cell types of the mature organism. In contrast, adult (somatic) stem cells, including hematopoietic, muscle, cardiac, neural, and mesenchymal stem cells, generally have more limited potency, and their differentiated derivatives are thought to primarily populate the tissue of residence. The illustrations found in this section feature the processes by which different types of stem cells differentiate into downstream lineages and highlight markers that can be utilized to identify them.