In activated cells, growth factor stimulation leads to the activation of Cyclin D1 and CDKs, resulting in the phosphorylation of Rb during late G1 phase, the release of E2F, and the subsequent transcriptional activation of genes required for DNA synthesis and cell growth, thereby promoting GBM cell proliferation and growth (Almalki, 2023). Here, RB1 is linked to glioblastoma.