ESCs (Embryonic Stem Cells) are a population of Pluripotent, Self-renewing cells which can proliferate indefinitely and contribute to the formation of basically all cell types in vitro and in vivo. The study of mammalian ESCs, especially Mouse ESCs, has provided valuable insights into early embryogenesis in mammals. Mouse ES cells are derived mainly from the ICM (Inner Cell Mass) of the Mouse Blastocyst embryos and retain this developmental identity even after prolonged culture in vitro. Both cell Extrinsic and Intrinsic factors regulate Mouse ESC Self-renewal and Pluripotency. Cell extrinsic factors include LIF (Leukaemia Inhibitory Factor) and BMP (Bone Morphogenic Protein), which signal through STAT (Signal Transducer and Activator of Transcription) and SMAD (Sma and MAD (Mothers Against Decapentaplegic) Related Protein) proteins, respectively. Recent evidences indicate that WNT (Wingless-Type [...]