OLIG2 and neoplasm: This notion is further supported by the analysis of expression array data using the bacTRAP olig2 RP-eGFP reporter system and immunostaining, which suggest that recruited olig2 cells can acquire expression of GFAP and vimentin and increase the expression of nestin as compared to the tumor olig2 cells, triple co-expression of which is considered to be typical for the bona fide neural stem cells.