CDKN2A and central nervous system cancer: While this vector was not robust at glioma initiation (<10% incidence), injections of RCAS-RSR and RCAS-Cre into Ntv-a Ink4a/Arf-/-Ptenfl/fl mice could give rise to high-grade gliomas that did not express PDGFRα and contained regions of proliferating cells that did not express mRFP (Figure S5d,e,g).