Humans have around 30 trillion cells in our adult bodies. Amazingly, each of these cells came from a handful of about 100 stem cells in the earliest days of development. The ability of these embryonic stem cells to turn into any cell type makes them pluripotent — something that researchers are harnessing in science and medicine today.
The use of human embryonic stem cells in research began in 1998, when several human embryos were donated from couples undergoing in vitro fertilization. From these embryos, scientists generated a virtually unlimited supply of pluripotent cells. Almost 30 years later, these embryonic stem cell lines are still used in many research labs today.