An amniotic epithelial cell is a form of stem cell extracted from the lining of the inner membrane of the placenta. Amniotic epithelial cells start to develop around 8 days post fertilization. These cells are known to have some of the same markers as embryonic stem cells, more specifically, Oct-4 and nanog. These transcription factors are the basis of the pluripotency of stem cells. Amniotic epithelial cells have the ability to develop into any of the three germ layers: endoderm, mesoderm, and ectoderm. They can develop into several organ tissues specific to these germ layers including heart, brain, and liver. The pluripotency of the human amniotic epithelial cells makes them useful in treating and fighting diseases and disorders of the nervous system as well as other tissues of the human body. Artificial heart valves and working tracheas, as well as muscle, fat, bone, heart, neural and liver cells have all been engineered using amniotic stem cells. Tissues obtained from amniotic cell lines show promise for patients with congenital diseases or malformations of the heart, liver, lungs, kidneys, and cerebral tissue.