Embryonic stem (ES) cells

Cell lines derived from early embryos that have the potential to differentiate into all types of somatic cells as well as to form germ line cells, and hence whole animals, when injected into early embryos.

An embryonic cell that can replicate indefinitely, transform into other types of cells, and serve as a continuous source of new cells.

Primitive (undifferentiated) cells from the embryo that have the potential to become a wide variety of specialized cell types.