Experiments carried out by a team at University College London has uncovered clues in what causes the disease to migrate from one part of the body to another. In many cases death is not caused by the primary tumour, but the secondary growth. The key follows experiments carried out by a team at University College London using frog and zebrafish embryos. Scientists identified a mechanism which called ‘chase and run’ which showed how diseased and healthy cells follow each other around the body. “Nobody knew how this happened, and now we believe we have uncovered it. If that is the case it will be relatively easy to develop drugs that interfere with this interaction," said Prof Roberto Mayor, who led the team.