The genetics of endocrine cancers is clearly an area where new scientific discoveries that have occurred in the past few years have already been translated into clinical practice. This volume attempts to provide a state-of-the-art review of some of the most relevant inherited syndromes that share a higher susceptibility to the development of endocrine tumors. It focuses on familial tumor syndromes for which the primary gene defect has been well characterized or recently identified. An overview of cloning strategies and gene characterization in cancer, is combined with detailed discussions of clinical aspects and molecular features of heritable endocrine neoplastic diseases, such as MEN1 and MEN2 and Von Hippel-Lindau disease. Studies on the PTEN gene, the first known phosphatase to lead to cancer when disrupted are discussed in detail. Also included disrupted is the recent identification and partial characterization of one of at least two genes for Carney Complex, PRKARIA. The authors place special emphasis on testing and screening strategies which now allow a much earlier identification of family members at risk. The challenge for the 21st century will be to develop equal progress in pharmacological prevention and cure based on the knowledge of the function of these susceptibility genes and their targets.