From:  New phase therapeutic pursuits for targeted drug delivery in glioblastoma multiforme

Schematic representation exhibiting p53 and RB pathways at the tumor site. SMAD3/4: small mothers against decapentaplegic 3/4; ATM: ataxia telangiectasia mutated; ATR: ataxia telangiectasia and rad3-related; Chk2: checkpoint kinase 2; CDK2: cyclin dependent kinase 2; HDAC: histone deacetylase; E2F: E2 factor; CDC25: cell division cycle 25; GSK 3β: glycogen synthase kinase 3 beta; G1 phase: growth 1 phase; S phase: synthesis phase; TGF-β: tumor growth factor-β