Based on the international workshop GPCRs: From Deorphanisation to Lead Structure Identification, held in Berlin in May 2006, the book highlights the following topics: Structure of GPCRs, Design of GPCR Ligands, GPCR Signalling, Deorphanization and Assay Development. All chapters are written by leading experts in the field, discussing the most recent state of the art. They give insight into the approaches taken by industry and academia to address GPCRs and depict how mature this target class-oriented research has become in the last decade. The book reflects the actual trends in the fast-emerging field of GPCR research in academia and industry.