Cells that undergo epithelial to mesenchymal transition (EMT) acquire increased migratory capabilities. In order for a cell to migrate to another location, it must first invade the surrounding tissue by entering through localized regions of disassembled basement membrane. Specialized regions of a cell that protrude through the basement membrane and initiate invasion under pathological conditions are termed invadopodia. The related structures, podosomes, are present in osteoclasts during the physiological process of bone remodeling. Invadopodia are Actin-rich membrane protrusions that accumulate MMPs necessary for extracellular matrix (ECM) remodeling and are hypothesized to contribute to the early stages of metastasis in vivo.