MMP14 and cancer: Given that cancer invasion relies on both cancer cell migration and extracellular matrix degrading MMPs, which are predominantly produced by non-cancerous stromal cells [44], we speculate that the major role of the MMP14-generated, short sBSG variant is to induce MMP activity in surrounding stromal cells, whereas the ADAM12-generated, long sBSG variant [18] mainly activates the migration of cancer cells in an auto- or paracrine manner.