Introduction to stem cell therapy.

Stem cells have the ability to differentiate into specific cell types. The 2 defining characteristics of a stem cell are perpetual self-renewal and the ability to differentiate into a specialized adult cell type. There are 2 major classes of stem cells: pluripotent cells, which can become any cell in the adult body, and multipotent cells, which are restricted to becoming a more limited population of cells. Cell sources, characteristics, differentiation, and therapeutic applications are discussed. Stem cells have great potential in tissue regeneration and repair, but much still needs to be learned about their biology, manipulation, and safety before their full therapeutic potential can be achieved.