Aging is an almost universal process within biological systems, one which leads to a decline in functional capacity, disease onset, and eventually death. There has been much interest in recent years to elucidate the molecular mec- nisms that underlie the aging process. Many theories have been proposed since the last century that aim to explain the causes of aging. There is no one theory that completely satisfies the phenotype of aging, but genetics and environm- tal factors play an important role in the etiology of age-related pathologies and the aging process. However, there is still much to be learned about the aging process which has been termed one of the last great frontiers in biology. De- graphic changes worldwide are leading to increased average life expectancies within our populations. These changes in population characteristics will impact upon the economies of the supporting society, with increasing healthcare and infrastructural costs arising from the prevalence of age-related pathologies and other physical disabilities associated with advancing years. Many researchers worldwide are working in the attempt to identify key cellular processes through which it might one day be possible to slow down the aging process and thus increase the health span of humans. Numerous research projects—from the cellular through to tissue, organ, and whole organism studies—are currently underway to investigate the mul- factorial aging process.