The consequences of not having efficient telomere maintenance would therefore be catastrophic. In fact, several mutations in telomerase have been identified in patients suffering from premature aging syndromes, with phenotypes ranging from bone marrow failure, where hematopoietic stem cells are unable to generate functional blood cells, to liver cirrhosis, where liver cells progressively become replaced by scar tissue. In addition to these “telomere syndromes”, we now understand that telomere erosion is also associated with several diseases of human aging and aging-related processes that occur in our later decades of life. These include cardiovascular diseases, diabetes, cancer and cognitive decline. In fact, telomere erosion is now seen as a disease potentiator and mortality predictor in the elderly. However, the molecular mechanism linking telomere erosion to loss of tissue fitness in the broad elderly population (individuals without genetic mutations in telomerase) is unknown.