The netrin receptor UNC-40 promotes invadopodia-to-invasive protrusion transition within the AC. In wild-type animals (top) numerous invadopodia turn over before one penetrates the basement membrane. The UNC-40 (DCC) receptor enriches at the basement membrane breach and through its effectors generates F-actin that builds a large stable protrusion. This invasive process physically displaces basement membrane (BM) and directs invasion through a single basement membrane gap into the underlying vulval tissue. UNC-6 (netrin) secreted from the VNC activates UNC-40, but a distinct mechanism recruits UNC-40 to sites of basement membrane penetration. In the absence of UNC-40 signaling, invadopodia fail to transition into an invasive protrusion and invadopodia persist, generating multiple breaches that inefficiently clear gaps in the basement membrane.