Working with colleagues from Germany and the US, researchers at Leipzig University have achieved a breakthrough in research into how cancer cells spread. In experiments, the team of biophysicists led by Professor Josef Alfons Käs, Steffen Grosser and Jürgen Lippoldt demonstrated for the first time how cells deform in order to move in dense tumor tissues and squeeze past neighboring cells. The researchers found that motile cells work together to fluidise tumor tissue.