<unk>  is normally expressed in the trophectoderm of the developing embryo, with its receptor<unk> R expressed throughout the inner cell mass. As embryonic stem cells are derived from the inner cell mass at the blastocyst stage, removing them from the inner cell mass also removes their source of<unk> . Recombinant<unk>  has been produced in plants by InVitria.
Leukemia inhibitory factor
Macrophage colony-stimulating factor
Colony-stimulating factor
Macrophage-activating factor
Major basic protein
Leukocyte-promoting factor
Hemopoietic growth factor
Interleukin