This book extensively discusses the biology of telomere with the help of advanced information. Developments in telomere researches have provided an interrelation of telomere dysfunction with cellular aging and several age-related human diseases. Some new findings and studies have further widened our knowledge of telomere functions, where telomeres have been demonstrated to be essential for microbial pathogen virulence and telomere proteins have significant non-telomeric cellular functions. This book presents current opinions on selected areas of telomere research and their implication, in the hope of benefitting interested individuals in their future studies and enhancing their research progress.