Book excerpt: This first of two volumes provides a general overview of the genetics, structure, mechanism and regulation of the Ras superfamily proteins and describes in detail the signaling pathways and processes regulated by specific members of this family. The focus of this first volume is on the Rho and Ras subfamily of small G proteins. Renowned scientists provide insights into the biochemistry of the classical and non-classical small G-protein family members, their spatio-temporal regulation, their effectors and their roles in health and disease. Together with Volume 2, this book provides a comprehensive and state-of-the-art work on small G-proteins (GTPases). It is intended for graduates and professors in biochemistry and cell biology already working on small G-proteins (small GTPases), but also offers an extremely valuable resource for those readers who are new to the field.