This book provides perspective; covers recent developments in technologies that have enabled the expanded use of biomarkers and discusses biomarker characterization and validation and applications throughout the discovery-development continuum. Importantly, several case studies of biomarkers that have helped and hindered decision making are presented, as well as an overview of the areas where proper use of biomarkers can substantively impact timelines and costs by streamlining development programs, enabling selection of better compounds and reducing late stage attrition, and facilitating personalized medicine. A book like this focusing on how to identify, develop, and truly integrate biomarkers can shape biomarker testing and use and enhance pharmaceutical decision making.