text_1: Assembly of invadopodia is triggered by focal generation of phosphatidylinositol-3,4-biphosphate and the activation of the nonreceptor tyrosine kinase Src.
text_2: Cortactin phosphorylation is required to release this inhibition so cofilin can sever actin filaments to create barbed ends at invadopodia to support Arp2/3-dependent actin polymerization.