PTEN and central nervous system cancer: Moreover, while transplantation of single-sorted CD133-positive cells resulted in gliomas contaminated by the eGFP-positive progeny, without the expansion of progeny cells in some cases (Figure S9e–j; Figure 6h), transplantation of purified CD133-positive recruited eGFP-negative cells from Ntv-a Ink4a/Arf-/-Ptenfl/fl or Ntv-a Ink4a/Arf+/-Pten+/fl mice did not result in glioma formation, suggesting that in hPDGFb-driven murine gliomas, tumorigenicity lies in the CD133-negative recruited cell subset (Figure 6g).