GFAP and neoplasm: Tissue-specific promoters can be used to selectively introduce oncogenes into nestin-positive neural stem and progenitor cells (Ntv-a), glial fibrillary acidic protein (GFAP) -positive glial cells (Gtv-a), or CNPase-positive oligo-dendroglial cells (Ctv-a), thereby enabling studies of the tumor cell of origin in glioma GEMMs [159].