RB1 and glioblastoma: The next-generation oncolytic adenovirus, Delta24-RGD (DNX-2401), has a 24 bp deletion in the adenovirus E1A gene and an RGD motif in fiber protein, which is selectively optimized for replication in GBM, due to commonly mutated Rb pathways, while sparing prevents post-mitotic cells [75,76,77].