Invasive cancer cells develop special membrane protrusions called invadopodia for migration. Invadopodia have two main structural components — F-actin and actin regulators. The formation of an invadopodium begins with the activation of cortactin — a nucleation promoting factor. Cortactin then recruits cofilin activated WASP and Arp 2/3 complexes near the membrane. Next, cofilin dissociates from cortactin and starts severing actin filaments to generate free barbed ends for elongation. The WASP and Arp2/3 proteins initiate new actin branches, pushing the membrane out, and elongating the invadopodium. Soon after, fascin starts crosslinking the actin filaments to form parallel actin bundles within the invadopodium core. As the invadopodium matures, the kinesins use the colocalized microtubule network to deliver vesicles with ECM-degrading proteases to the cell membrane. The cancer cells release these proteases to break down the ECM and intravasate into a blood vessel. Here, cortactin phosphorylation destabilizes the branched actin network and disassembles the invadopodia. Similar to intravasation, the circulating cancer cells also use invadopodia to extravasate into the tissue and form secondary tumors.