With each round of DNA replication that occurs when a cell divides, a little bit of the telomere wears away. Current research suggests that once a cell has replicated a certain number of times, the telomere degrades to such a point that the cell commits suicide. Telomere research is gaining momentum on several fronts. Many laboratories are investigating the role of telomeres in aging and death. Cancer researchers are also very interested in telomeres.
Many cancer cells appear to owe their immortality to a switched on telomerase gene.