Scientists have long explored using viruses to fight cancer, but that doesn’t work well for metastatic cancers (that is, those that have spread beyond the primary site) when your immune system will quickly neuter perceived threats. There might, however, be a solution. A team of Case Western Reserve and Emory researchers has modified human adenovirus to create a “stealth” weapon against metastatic cancers. Key mutations and protein changes reduce the chances of the immune system deactivating the virus, trapping it in the liver or producing a dangerous inflammatory reaction.

The approach would not only be safer, but would spare doctors from having to deliver viruses directly to tumor sites and could treat more than just the main tumor. It could be reworked for different types of cancer and even include genes and proteins that foster cancer immunity.