A Report by Axel WagnerWhy do cancer cells seem to live eternally, and why do other cells of the body die after a certain time? Molecular biologist Maria Blasco at the Spanish Cancer Research Center in Madrid is looking into these questions.And she has found the answer in the cells’ chromosomes. The ends of the chromosomes determine how old a cell can become. This knowledge may some day help us develop new cancer medicines – and perhaps even extend the life expectancies of cells and people.