Pluripotent stem cells are a type of stem cell that can give rise to every other cell type in the body, such as neurons, heart, pancreatic, and liver cells. They are particularly potent and normally only exist during early embryonic development. The definition of pluripotent stem cell is based on two properties: self-renewal and potency. The self-renewal is the capacity of the stem cells to divide and create an identical copy of themselves, while potency refers to the ability of the stem cells to differentiate into all cell types of the organism. Pluripotent stem cells can be generated directly from a somatic cell, such as skin cells, through a process called induced pluripotent stem cell (iPSC) technology. The most well-known type of pluripotent stem cell is the embryonic stem cell, which can be derived from the inner cell mass of a pre-implantation stage embryo. However, the use of embryonic stem cells has been controversial due to the destruction or manipulation of the embryo involved in their generation.