This volume provides broad insights to the most recent discoveries in telomere biology, with current applications in tumour 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. Twenty-eight chapters were written by a group of research scientists, working in the telomere/telomerase fields today.