Book excerpt: This volume compiles new experimental approaches and concepts focusing mostly, but not solely, on ways to manipulate and regulate Ras activity and its downstream signaling output. Chapters detail standard methodologies, biochemical methods, Ras processing trafficking and localization, Ras signaling and inhibition, and in vivo models for studying Ras function. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, application details for both the expert and non-expert reader, and tips on troubleshooting and avoiding known pitfalls. Authoritative and accessible, Ras Activity and Signaling: Methods and Protocols aims to provide support and guidance to lab workers in their work on Ras GTPases and in the design of new projects requiring novel methodologies.