Telomeres maintain the integrity of DNA in chromosomes of a cell. They are analogous to caps at the end of a rope that prevent the fibers from fraying. The telomeres shorten with each replication during mitosis. Therefore, they are associated with aging since a cell would not replicate with very short telomeres. In cancer, telomerase (that generates the telomeres) is often active and help the sustenance of cancer cells during their proliferation and active mitosis.
