A major obstacle to the successful therapeutic use of oligonucleotides is their poor delivery to target cells. This is a particular problem for therapies developed to treat brain diseases, such as glioblastomas. However, a number of research teams are working on strategies to improve the passage of oligonucleotides across the blood:brain barrier. The latest progress in this respect was reported at the IIR Ltd conference, entitled ‘Antisense Therapy: Efficacy and Delivery of Antisense & Ribozyme Oligonucleotides’ [London, UK; February 1995].