Jumping genes are genetic parasites found in bacteria, plants, animals, and humans. Some jumping genes can also remove themselves from RNA with the help of an RNA enzyme. Genetic family tree studies show that such transfers have occurred, but scientists have generally assumed that jumping genes traveled as passengers inside plasmids or viruses. In humans, circular RNA molecules influence many metabolic processes, and their role in tumor development is currently the subject of intensive research. Our study has shown that in microorganisms jumping genes can be transferred to other species via their circular RNA," says Jens Harder.