Summary of cell phenotypes resulting from inhibition of WASP family members. (Top) Control. All pathways are intact and regulated. (Top, N-WASP KD) Lamellipod extension containing dendritic network is normal. The only difference is the absence of ventral protrusions called invadopods (Yamaguchi et al., 2005). (Top, WAVE2 KD) Inhibition of lamellipods and loss of dendritic network but not invadopods. Lamellar structures are more prominent. (Top, N-WASP/WAVE2 KD) Inhibition of both N-WASP and WAVE2 results in loss of lamellipods and invadopods and activation of the mDia1 pathway, leading to the formation of a prominent lamella, filopods, and jagged protrusions. (Bottom, 1) The N-WASP-Arp2/3 complex is necessary for invadopod formation (Yamaguchi et al., 2005). (Bottom, 2) WAVE2 regulates lamellipod formation, not filopod formation. (Bottom, 3) Inhibition of both WAVE2 and N-WASP up-regulates RhoA and mDia1 activities, resulting in lamellar but not lamellipodial extension.