Distinction at the leading edge of the cell

Cell locomotion is governed by spatially and temporally co-ordinated changes in the organization of the actin cytoskeleton. In the highlighted manuscript,((1)) the authors focus on actin remodelling at the front of moving cells to reveal the existence of two distinct yet spatially overlapping actin networks that play largely independent yet fundamental roles in cell migration. The first is defined as the lamellipodium, which assembles and disassembles within the first 3 microm of the leading edge. This serves to promote the random protrusion and retraction of the leading edge but has no role in productive cell translocation. The second actin network, the lamella, is responsible for the advancement of the cell by integrating contraction with cellular adhesions.