Timing, racing, combating, struggling and targeting are some actions through which cellular fate could be reflected and evaluated. Interaction between cell territory and environment occur during pre-embryonic, fetal development, and post-natal periods. What the researchers observe as the outcome of telomeres behavior is only the peak of an ice mountain within a stormy ocean. Cellular life depends on programmed behavior of telomeres, capable to surprise the cells. Telomeres provide an introduction to the history of our cells which govern the quality of life and status of health. Telomeres as the cooperative territory are capable of stabilizing the chromosomal territory. The status of telomeres reflects the key information, announcing the real age of individuals, and may be a valuable marker for prognosis and predicting cancer. Telomere territory is characterized with a multi-disciplinary manner. Therefore, this book is aimed to offer a wide range of chapters, hoping to be useful for diverse audiences, including hematologists-oncologists, radiotherapists, surgeons, cancer researchers, and all the sectors who affect the macro- and micro- environmental domains. Finally, telomeres are sensitive, cooperative, and trustable targets. It is worth to state that ‘telomeres are messengers of NATURE’, let’s to know them as they are.