Stem cells, which have the potential to develop into many different cell types in the body, act like a repair system for the body.
They theoretically can divide without limit to replenish other cells as long as the person or animal is alive.
When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.
Source: National Institutes of Health
