ABSTRACT

The ‹rst derivation of embryonic stem cells (ESCs) from human embryos in 1998 ushered in a new era in cell biology and biomedical research. Human ESCs (hESCs) are a unique cell type, de‹ned by their unlimited self-renewal capacity and potential to differentiate to any cell type in the human body. Therefore, these cells not only provide the opportunity to investigate the developmental events that occur during human embryogenesis but also offer a new source of cells for regenerative medicine, drug discovery, and toxicity screening (Figure 1.1). In addition, these cells can be used to study cell commitment and (re)programming of fate, as well as the molecular mechanisms of complex diseases. However, to maximize the value of hESCs, we need to be able to control their differentiation potential and to be able to promote the development of speci‹c cell types.