Model for Rho-GTPase signaling control of invadopodial formation and function. In response to the interaction of tumor cells with their 3D matrix environment, Rho-GTPases are activated locally, triggering actin assembly through activation of the Arp2/3 complex and leading to invadopodia protrusion within the ECM. IQGAP1, which is downstream of Cdc42 and RhoA, plays a central role in invadopodia function through the coordination of actin assembly with the exocytic machinery via the vesicle-docking exocyst complex and possibly through microtubule plus end anchoring (see Discussion for details).