High Quality Content by WIKIPEDIA articles! Amniotic epithelial cells are a form of stem cells extracted from the placenta, and may become useful in fighting diseases and disorders of the nervous system. 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 suffering from congenital diseases or malformations of the heart, liver, lungs, kidneys, and cerebral tissue.