Before revision: During cell migration, cells become polarized, change their shape, and move in response to various cues, both internal and external .
After revision: During cell migration, cells become polarized, change their shape, and move in response to various cues, both internal and external cues. Cell polarization is defined through the URLanization of molecules such as PI3K or small GTPases, and is determined by intracellular signaling networks. It results in directional forces through actin polymerization and myosin contractions.