Abstract
In this chapter, we will discuss aging as the progressive decline in the function of cells, tissues and organs that leads to impaired functions of our body. Accordingly, older age is the primary risk factor for non-communicative diseases, such as cancer. Common hallmarks of aging are cellular senescence, genome instability, epigenetic alterations and telomere attrition. Interestingly, epigenetic signatures can serve as biomarkers of aging, since the process is associated with specific chromatin patterns and chromatin modifiers that are able to modulate both life- and healthspan. The shortening of telomeres has on one hand a tumor-suppressive effect, since it induces cell cycle arrest, but on the other hand it can also lead to extensive genome instability that promotes cancer progression.