Use of a genetic glioblastoma models such as triple Pten, Trp53, and Rb1 mutation induction via a Cre-loxP system also encounters a long accelerating tumour growth period of approximately 100–200 days, and though these mice have a functional immune system, the growth location of each individual tumour is unpredictable37. This evidence concerns the gene RB1 and glioblastoma.