Actin is one of the structural and functional units of the cytoskeleton and has a pivotal role in the maintenance of cell shape and motility, thanks to its capability of assembling into filaments, which are referred to as actin microfilaments or F-actin to distinguish this form from the unassembled globular G-actin. In particular, proper cell functioning depends on the dynamic and mechanical properties of F-actin. Therefore, abnormalities in the mechanisms of assembly may lead to the development of numerous pathologies. Actin belongs to a protein family that includes six different isoforms that share a remarkably high sequence similarity but differ in tissue expression and cellular localization.