During cancer metastasis, tumor cells acquire the ability to leave their original environment and migrate through possibly harsh conditions. Vimentin is a protein of the cell’s cytoskeleton which is highly expressed in tumuorigenesis and also in other examples of collective cell migration, like wound healing, and is known to contribute to cell motility. In our research we dwell into the effect of vimentin in breast cancer cells, using 2 cell lines, one which naturally expresses vimentin and one for which we had silenced the vimentin expression. We find differences in the elastic properties between the cell types, the vimentin expressing cells being significantly softer. We also compare the motility by various experiments, ranging from tracking single cells to measuring collective migration in wound healing. Our results confirm that vimentin enhances cell motility, but we find that it does it in a density dependent manner – For isolated cells the 2 cell types behave similarly, but vimentin expressing cells are much more able to persist in their movement in crowded conditions, where cell-cell interactions become dominant. We suggest a link between the elasticity and the density controlled motility, based on a simplistic physical model.