The proliferating field of neural crest stem cells.

Neural crest stem cells were first isolated from early embryonic neural crest in the early 1990s, but in the past 5 years, there has been a burst of discoveries of neural crest-derived stem cells from diverse locations. Here, we summarize these data, highlighting the characteristics of each stem cell type. These cells vary widely in the markers they express and the variety of cell types they appear to generate. They occupy diverse locations, but in some cases multiple stem cell types apparently occupy physically proximate niches. To date, few molecular similarities can be identified between these stem cells, although a systematic comparison is required. We note other issues worthy of attention, including aspects of the in vivo behavior of these stem cells, their niches, and their lineage relationships. Together, analysis of these issues will clarify this expanding, but still young, field and contribute to exploration of the important therapeutic potential of these cells.