NCIt definition : Telomeres in human cancer cells consist of a tandem array of telomeric DNA repeats
bound to a specialized telomeric proteins. Telomeres allow cells to distinguish natural
chromosome ends from damaged DNA. When telomere function is disrupted, a potentially
lethal DNA damage response can ensue, DNA repair activities threaten the integrity
of chromosome ends, and extensive genome instability can arise. Both telomerase and
recombination can lengthen telomeres. (from PMID 11850780 and NCI);