Discovering pluripotency: 30 years of mouse embryonic stem cells

This year marks the thirtieth anniversary since embryonic stem (ES) cells were first isolated from mouse blastocysts. In this Timeline, one of the scientists to isolate mouse ES cells in 1981 gives a personal account of the ideas that led to, and followed, this milestone. Embryonic stem (ES) cells are pluripotent cells isolated from an early embryo and grown as a cell line in tissue culture. Their discovery came from the conjunction of studies in human pathology, mouse genetics, early mouse embryo development, cell surface immunology and tissue culture. ES cells provided a crucial tool for manipulating mouse embryos to study mouse genetics, development and physiology. They have not only revolutionized experimental mammalian genetics but, with the advent of equivalent human ES cells, have now opened new vistas for regenerative medicine.