Because of the current progress in molecular medicine (genomics, proteomics), a plethora of new and often human-specific targets are being identified. These targets often play a significant role in the pathogenesis of diseases, and identifying them offers the potential for early diagnosis and intervention. An early in vivo validation of specific ligands binding to these targets in humans is needed to as sess their potential for targeted imaging and radiotherapy. Further- VI Preface more, such validation studies may allow for a better understanding of the molecular processes underlying...