Summary: During cytokinesis. a contractile ring consisting of unbranched filamentous actin (F-actin) and myosin II constricts at the cell equator. Unbranched F-actin is generated by formin. and without formin no cleavage furrow forms. https://www.diegojavierfares.com/quick-grab-can-Ichnusa-Beer-1x33cl-best-save/