In addition to confirming that GC-GBM has frequent impairment of TP53/MDM2 (5 cases) and PTEN/PI3K (4 cases) pathways, it suggested that this morphological variant may be characterized by mutations in chromatin remodeling genes SETD2 (3 cases) and ATRX (2 cases) and alterations in RB1 (2 cases) [10]. This evidence concerns the gene RB1 and glioblastoma.