Nestin is a type IV intermediate filament protein that is expressed in dividing cells during early stages of Central Nervous System (CNS) and Peripheral Nervous System (PNS) development, as well as that of myogenic and other tissue types. Nestin facilitates processes of cellular rearrangement such as migration and mitosis, which are characteristics of undifferentiated cells. Nestin was first identified in the nervous system present in mitotically active central and peripheral progenitor cells that developed into neurons and glia during early neurogenesis. Studies have shown that Nestin is expressed in proliferating endothelial cells, thus, may serve as an important marker for angiogenesis. Overexpression of nestin has been clinically linked to human gliomas, as well as tumors of the CNS such as astrocytoma, ependymoma, oligodendroglioma, glioblastoma, and primitive neuroectodermal tumors. Nestin expression has also been indicated in prostatic adenocarcinoma, pancreatic ductal carcinoma, thyroid carcinoma, and mesenchymal tumors such as gastrointestinal stromal tumor and dermatofibrosarcoma protuberans. Reports have suggested that nestin is significantly overexpressed in melanoma, and linked to more advanced stages of the disease.