Human embryonic stem cells

Embryonic stem (ES) cells are cells derived from the early embryo that can be propagated indefinitely in the primitive undifferentiated state while re maining pluripotent; they share these properties with embryonic germ (EG) c ells, Candidate ES and EG cell lines from the human blastocyst and embryoni c gonad can differentiate into multiple types of somatic cell. The phenotyp e of the blastocyst-derived cell lines is very similar to that of monkey ES cells and pluripotent human embryonal carcinoma cells, but differs from th at of mouse ES cells or the human germ-cell-derived stem cells. Although ou r understanding of the control of growth and differentiation of human ES ce lls is quite limited, it is clear that the development of these cell lines will have a widespread impact on biomedical research.