Most cells in the body, like skin or nerve cells, can only carry out very specific roles and are called specialised cells. Stem cells are different because they possess two unique features; the ability to make many copies of themselves (self-renewal), and to produce specialised cells such as skin cells, immune cells, or nerve cells (differentiation).
Pluripotent stem cells (PSCs) are sometimes called “true” or “embryo” stem cells because they can turn into almost any type of cell in the body. After embryonic development we stop producing these types of stem cells naturally, but maintain a variety of specialised stem cells.
In 2006 researchers showed that it was possible, in the lab at least, to turn adult cells back into pluripotent stem cells.
Hematopoietic stem cells (HSCs) are a type of adult stem cell made in the bone marrow, which have the ability to produce the different cells found in the blood, including immune cells.
Mesenchymal stem cells (MSCs) are found in many parts of the body and are usually taken from bone marrow, skin and fat tissue. They can produce many different types of cells, including muscle and cartilage.