On the left: Super-resolution microscopy image of a migrating human osteosarcoma cell. Magenta marks focal adhesions, and green non-muscle myosin II (NMII). F-actin bundles are shown in grey. On the right: Schematics of cortical stress ?ber assembly process. Myosin II pulse orchestrates the initial assembly and maturation of a cortical stress ?ber, followed by focal adhesion maturation at the ends of the contractile bundle. Note that the color-coding is di?erent between the two panels.