During the process of development, neural crest cells migrate out from their 
niche between the newly formed ectoderm and the neural tube. Thereafter, they 
give rise not only to ectodermal cell types, but also to mesodermal cell types. 
Cell types with neural crest ancestry consequently comprise a number of 
specialized varieties, such as ectodermal neurons, melanocytes and Schwann 
cells, as well as mesodermal osteoblasts, adipocytes and smooth muscle cells. 
Numerous recent studies suggest that stem cells with a neural crest origin 
persist into adulthood, especially within the mammalian craniofacial 
compartment. This review discusses the sources of adult neural crest-derived 
stem cells (NCSCs) derived from the cranium, as well as their differentiation 
potential and expression of key stem cell markers. Furthermore, the expression 
of marker genes associated with embryonic stem cells and the issue of multi- 
versus pluripotency of adult NCSCs is reviewed. Stringent tests are proposed, 
which, if performed, are anticipated to clarify the issue of adult NCSC potency. 
Finally, current pre-clinical and clinical data are discussed in light of the 
clinical impact of adult NCSCs.