VIM and choroid plexus neoplasm: It is important to note however the high expression of Vimentin (Vim) by nearly all choroid plexus tumors suggests a vascular cell abnormality, while the presence of the astrocytic marker glial fibrilliary acidic protein (Gfap) in up to 50% of plexus neoplasms suggests some conversion of epithelial cells to glial lineages (Rickert and Paulus, 2000), as has been reported for plexus implantation in spinal cord (Ide et al., 2001; Kitada et al., 2001).