CTTN and neoplasm: Cortactin is an actin 2/3 (Arp2/3) complex activating and filamentous (F) actin-binding protein that is associated with tumor cell invasion and migration.[45] According to Rothschild et al,[13] HNSCC cells with cortactin overexpression show higher Arp2/3 complex activity and are more aggressive and migratory than HNSCC cells without cortactin overexpression.