Carol W. Greider and Elizabeth Blackburn both won the 2009 Nobel Prize in Physiology or Medicine for their discovery that telomeres are protected from progressive shortening by the enzyme telomerase. An organism's genes are stored within DNA molecules, found in chromosomes inside the nuclei of cells. When cells divide, it's crucial their chromosomes be copied in full and not damaged or altered. At each end of a chromosome lies a cap of genetic material that protects it called a telomere. This is a great story of women in science supporting each other and working together to achieve amazing feats. Carol received her PhD from the University of California, Berkeley and Elizabeth was her supervisor. After Elizabeth discovered that telomeres have specific DNA that prevents chromosomal degradation, the two ladies worked together to discover telomerase, the enzyme that facilitates the production of the telomeres' DNA.