Cells must follow environmental cues and rearrange their internal components to migrate from one location to another. This is primarily achieved through actin-filament reorganization at the cell's leading edge. Actin is a multi-functional, globular protein that can polymerize to form polarized F-actin filaments with two distinguished ends – plus and minus. They form a tough and flexible framework that supports and strengthens the cell membrane. In response to appropriate signals, the actin monomers start assembling at the plus ends or branching at sides of existing filaments. Simultaneously, the minus ends depolymerize and sever, releasing actin monomers that can be recycled back to the polymerizing end. The continuous force generated by the directional polymerization of the actin filaments pushes the membrane outwards, forming membrane protrusions. These protrusions help the cell to adhere to the matrix, sense their immediate environment, and allow forward cell displacement by retraction.