RB1 and gliosarcoma: Lastly, there are few reports of comprehensive genome sequencing of gliosarcomas, which have described key somatic mutations in known oncogenes including TP53, PTEN, RB1, and NF1 as well as amplification events of EGFR, CDK4/6, PDGFRA, MDM2, AKT1, and MET42–44.