Telomerase is an enzyme that helps maintain the length of telomeres, which are protective caps at the ends of chromosomes. As cells divide, telomeres shorten, leading to aging and cell death. Telomerase adds repetitive nucleotide sequences to the telomeres, allowing cells to divide without losing important genetic information. This enzyme is particularly active in stem cells and cancer cells. In normal somatic cells, telomerase activity is low or absent, which limits their ability to divide. However, in many cancer cells, high levels of telomerase enable uncontrolled growth, making it a target for potential cancer therapies.