Prof Friedl discusses how the use of imaging deeply in to tumours can show scientists how tumours grow, where the cancer cells invade and what the consequences are for the healthy tissue. At NCRI he presented his experiments looking at the edges of sarcomas in mice as they grow. His results challenge the conventional idea that it’s single cancer cells that break away from the original tumour and invade the surrounding tissues. His videos show there are long strands of connected cells sprouting out of the primary tumour, which grow along pre-existing blood or lymph vessels – the "tracks of least resistance". Read more at