Nestin is a class VI intermediate filament protein expressed predominantly in stem cells of the neural tube but absent from virtually all differentiated CNS cells. In the CNS, nestin is downregulated upon differentiation and replaced by neurofilaments. Transient expression of nestin has been postulated as a key step committing cells to the neural differentiation pathway. Nestin expression has also been observed in pancreatic hematopoietic stem cell populations.
