In fact, GBM was fully sequenced in 2008 and investigators found that retinoblastoma protein (RB), tumor protein p53 (p53), and receptor tyrosine kinase/phosphatidylinositol 3-kinase (RTK/PI3K) pathways were deregulated in almost all GBM tumors [134]. This evidence concerns the gene RB1 and glioblastoma.