There are two types of stem cells , adult stem cells and embryonic stem cells .
- Adult stem cells are found in mature tissues (bone marrow, skin, brain etc) that can self-renew and give rise to other cell types from their tissue of origin, thereby producing a steady supply of new cells to maintain that tissue throughout life. In general, adult stem cells from one organ do not give rise to cell types from other organs.
Stem cells are unspecialized cells that have two defining properties: the ability to differentiate into other cells and the ability to self-regenerate.
According to The Harvard Stem Cell Institute, Stem cells are unique in their ability to self-renew: to divide and create two cells, each identical to the original. Understanding stem cell self-renewal is central to understanding how organisms are made and maintained, and may lead to insights that permit physicians to modulate tissue regeneration and repair in their patients.