Scientists are making strides in adapting various viruses to kill cancer - there is a certain satisfaction inherent in turning the tools of disease for use in healing. Medical News Today tells of another groups hard at work to this end: "an attenuated -- or non-virulent -- form of poliovirus is effective in obliterating neuroblastoma tumors in mice, even when the mice had been previously vaccinated against the virus. By its nature, poliovirus destroys the cells it infects in an attempt to replicate copies of itself. ... The [researchers] took advantage of this viral property by injecting a stable, attenuated strain of poliovirus directly into neuroblastoma tumors transplanted into 12 mice engineered to contract polio. The virus was able to destroy tumors in all 12 mice; however tumors reoccurred in two mice by the end of the 180-day study period. .... None of the mice experienced any ill effects from the virus itself. ... any viral particles that make it to the bloodstream would be destroyed by antibodies created through poliovirus vaccination. The researchers believe that their findings, if developed to work in humans, could represent a safe, practical means of treating [many] other cancers in adults."