This is reminiscent of other OV studies, where the ability to complete a full infectious cycle is dispensable for the priming of IFN-mediated anti-tumour immunity.20, 22, 27 Nevertheless, it is likely that replication-competent virus provides other clinical advantages when treating preimmune human patients, such as potential amplification at tumour sites,19 and cell-mediated carriage28 to mitigate existing antibody responses; whether the latter occurs for uv-inactivated virus is unknown, and this would currently be impossible to test in vivo given the absence of clinical grade reagent. The gene discussed is IFNA1; the disease is neoplasm.