Stem cells are important to health for a number of reasons. First, they are responsible for the repair and maintenance of our tissues and organs. When we injure ourselves, it is stem cells that rush to the site of the injury to begin the healing process. Second, stem cells are important for the production of new blood cells. Without a constant supply of new blood cells, we would quickly succumb to infection and disease. Finally, stem cells play an important role in the immune system. They help to identify and destroy foreign invaders, such as viruses and bacteria. Telomeres are important to health for a number of reasons as well. First, they protect our chromosomes from damage. Without telomeres, our chromosomes would quickly become damaged, and our cells would die. Second, telomeres help to regulate the aging process. As we age, our telomeres become shorter and shorter. Eventually, they become so short that our cells can no longer divide, and we die. Finally, telomeres have been linked to a number of diseases, including cancer. Cancer occurs when our cells divide uncontrollably. This uncontrolled cell division is thought to be linked to the shortened telomeres.