Swedish researchers say they have developed a DNA vaccine that restricts the supply of blood to tumors.
The finding is important because in order for a cancer tumor to grow, it must be able to stimulate the formation of new blood vessels.
So far the vaccine has only been studied in mice, but scientists say it shows great potential for humans.
Scientists behind the vaccine say that it may one day become a potential treatment against cancer.
The vaccination did not cause any undesired side-effects in the tested mice.