During the last century there have been sporadic reports of cancer remission following a virus infection. Researchers have investigated whether naturally-occurring viruses could be engineered to specifically target and destroy tumour cells. Much progress has been made and several such oncolytic viruses have entered clinical trials. However, their efficacy is hampered by their limited tumour-specific trafficking, and the immune system which has co-evolved to limit the infectivity and virulence of viruses. We plan to address these fundamental problems directly by manufacturing a new generation of chimeric viruses with improved therapeutic amplification at the tumour site, and the ability to survive in the body's circulation to target tumour metastases, which are the main cause of morbidity and mortality.