Stem cells are the body’s “master” cells and can develop into tissue, organ, blood and the immune system. The primary sources of stem cells are bone marrow, peripheral (circulating) blood, and umbilical cord blood.

Hematopoietic stem cells are “progenitor” or immature unspecialized cells of the hematopoietic system that have the potential to later develop into the cells of the blood and immune system:

1. red blood cells, which transport oxygen to the cells
2. white blood cells, which help fight disease
3. platelets, which are needed for blood clotting