Stem cells are pluripotent and can differentiate into many different structures. Their ability to differentiate and remain differentiated is key to the survival of complex multiorgan life forms such as humans. For instance, liver stem cells must remain liver cells, kidney stem cells must remain kidney cells, and skin stem cells must remain skin cells once they are differentiated, which is accomplished through epigenetic changes that repress certain gene sequences that should no longer be transcribed. If these gene sequences are mistakenly available for transcription, cancer may develop. In the cosmetics industry there is tremendous interest in stem cells as a source of materials for replenishing the aging body.