Several oncogenes are known to be involved in glioblastoma multiforme pathogenesis but no therapies are currently available. Jensen et al. evaluated an RNA interference spherical nucleic acid (RNAi–SNA) nanoparticle conjugate to neutralize oncogene expression in a mouse model of glioblastoma. Systemically delivered SNAs that targeted the oncoprotein BCL2-like protein 12 — which could penetrate the blood–brain barrier and blood–tumour barrier — increased intratumoral apoptosis and reduced tumour burden and progression. This suggests that silencing anti-apoptotic signalling using RNAi–SNAs could be a new approach for brain tumour therapy.