This volume provides broad insights to the most recent discoveries in telomere biology, with current applications in tumor diagnostics and future potentials in therapy. Special features of diverse organisms are presented, with ciliates, the telomerase discoverer organisms ; yeasts, the molecular genetisists' toy for eukaryotes ; including plants and insects as well. 28 chapters were written by a group of leading research scientists, working in the telomere/telomerase fields today. This book will be a core reference for any physician, scientist or educated reader with an interest in the exciting developments in this research field.Section I: Telomerases, Telomeres and Cancer.Section Ia: TelomeraseActivity and Cancer.1. The Significance of Quantitative Evaluation of Telomerase Activity and hTERT mRNA Expression in Colorectal Cancers; M. Pogessi, et al.2. The Role of Telomerase De-Regulation in Keratinocyte Immortality and the Progression of Human Head and Neck Cancer; E.K. Parkinson.3. Telomerase in Mesothelioma: Diagnostic and Therapeutic Applications; K. Dhaene.4. Telomerase Activity in Mesenchymal Tumors; R. Schneider-Stock, et al.5. Telomerase Activity in Neuroblastomas: A New Molecular Marker for Treatment Stratification and Prognostic Grouping; C. Poremba, B. Dockhorn-Dworniczak.5. Telomerase and Radiosensiticity of Human Tumors; T.K. Pandita.7. Amplification of hTERT, the Telomerase Reverse Transcriptase Gene in Human Cancers; D. Xu, et al.8. Telomerase Activity as a Marker ofl³Á