Why do you use ES cells and not adult stem cells?
Adult stem cells such as the mesenchymal stem cells isolated from bone marrow have a more restricted differentiation potential, i.e. they can differentiate into a more limited set of cell types such as those making up the haematopoietic system (including the bone marrow, red blood cells and lymphocytes). Depending on their source, adult stem cells can have distinct properties. ESNATS aims to build an "all in one" in vitro test system using a single cell type (ES cells) that have the potential to generate all cell types in the body.