Scientists have identified the long-sought telomerase RNA gene in a single-cell research model. Chromosomes shorten with every cell division. In stem cells and in cancer cells, this shortening is compensated by telomerase, an enzyme that adds short repeat sequences to the ends of chromosomes to replenish lost DNA. As telomerase is required for the continued growth of most cancer cells, the enzyme is considered a promising target for new anti-cancer drugs. A correlation between telomere length and a variety of diseases has further intensified interest in understanding telomerase and its regulation.