OLIG2 and central nervous system cancer: To rule out the possibility of spontaneous proviral excision or loss of eGFP expression in the originally infected cells in the virally induced gliomas, we performed transplantations of acutely isolated non-fluorescent hPDGFb-driven mouse glioma cells derived from Ntv-a gliomas induced by the non-fluorescent RCAS-hPDGFb vector into the bacTRAP olig2 RP-eGFP reporter mice, expressing a fusion between ribosomal protein L10a and eGFP (RP-eGFP) under the Olig2 promoter (Figure S3b–d) [14], [31], [32].