Stem Cells - a Definition

Professor Fred Gage defines the key features of stem cells, which include self-renewal and the ability to give rise to another cell.

A stem cell has really, two key elements to its definition. One is that it is self-renewing, which means, when it divides, one of its daughter cells can give rise to itself, but the other daughter cell can give rise to a more mature or differentiated cell. So those are the only features of the definition of a stem cell: self-renewal, and the ability to give rise to another cell that’s more mature. The real critical aspect about stem cells is the word that comes before, is it an embryonic stem cell, or is it a fetal stem cell, or is it an adult stem cell? And these terms, before stem cell, define where the stem cell comes from, so it could be from an adult brain or a developing liver, or it could be an embryonic stem cell. So, knowing where it comes from and how much potential it has is very important.