Book excerpt: Actin is one of the most widespread proteins in eukaryotic cells. This book and its companion (Molecular Interactions of Actin. Actin-Myosin Interaction, Actin-Based Regulation) provide an authoritative and opinionated view of the structure and function of this essential protein. Each section includes an historical perspective and a detailed commentary on actin protein chemistry, molecular and cell biology of actin. While some chapters review the body of knowledge of the subject, others contain new experimental data. This book will appeal to research scientists seeking contemporary overviews of actin and its binding proteins. Contributors include senior scientists as well as the new breed of younger scientists.