A reovirus that normally causes mild respiratory
infections in human beings has been found to be an effective killer of
cancerous tumors in mice.

According to a report in Science,
the reovirus uses the Ras pathway in the cells of mice, which normally
regulates cell growth. It is the Ras pathway that is activated in about
75 percent of human cancers.

Other viruses have been found to destroy tumors,
but this is the first virus that uses the Ras pathway. \”This is the
pathway everyone wants to target,\” said Peter Forsyth, an oncologist
at the University of Calgary. \”The treatment is very effective.\”

The main advantage of the reovirus is that
it doesn\’t seem to affect noncancerous cells. Clinical trials in human
beings are years away, however.