NES and glioma: We next sought to corroborate the tissue-specific effect of IDH1R132H in a spontaneous glioma mouse model, which combines the replication-competent avian sarcoma-leukosis virus long-terminal repeat with splice acceptor (RCAS) for transgene delivery [30–32] with a transgenic line (Nes-tva) carrying Nestin promoter-driven expression of avian retroviral receptor tva [33].