Stem Cells are undifferentiated cells that can give rise to several lineages of differentiated cell types. Stem cells are characterized by their ability to self-renew and maintain pluripotency. Embryonic stem cells (ESCs) maintain their pluripotent state by expressing a battery of transcription factors including OCT4, SOX2 and NANOG. Other factors such as FOXD3 and FGF4 are also believed to play important role in pluripotency and self-renewal. OCT4, SOX2 and NANOG form a regulatory feedback circuit that maintains pluripotency in human and mouse ESCs...