We generated the NestinCre/+; p53f/f; Ptenf/+; R26tdTomato/+ tumour model in which Cre-mediated recombination results in the activation of the tdTomato reporter as well as the homozygous and heterozygous deletion of the two tumour suppressors, Tp53 and Pten, respectively, genes that are mutated/deleted in many GBM patients60. The gene discussed is PTEN; the disease is glioblastoma.