Every embryo begins as a single fertilized egg, which develops into a human body consisting of trillions of cells, each one specialized to carry out specific functions. Since embryonic stem cells can differentiate into any type of tissue, they have the potential to treat an almost unending array of medical conditions — replacing damaged or lost body parts or tissues, slowing degenerative diseases, even growing new organs. Researchers working to understand how to manipulate this powerful tool get their supply from stem cell lines, groups of stem cells derived from animal or human tissue that can reproduce themselves indefinitely.
What Are They?
Stem cells can morph into all manner of specialized tissue cells. They are prized for their potential to treat many different kinds of medical conditions, as well as serving as a testing ground for drugs.