Actin Cytoskeleton in Cancer Progression and Metastasis – Part A, Volume 355 in the International Review of Cell and Molecular Biology series, provides an overview of the roles of the actin cytoskeleton and some of its key structural regulators, including WASp, Paxillin, Myosin, Testin, L-Plastin and profilin, in central processes underlying cancer progression and metastasis, such as changes in cell morphology and gene expression, acquisition of migratory and invasive capabilities, and evasion from the immune response.