As scientists continue to explore centenarian biochemistry, they are uncovering the details of its better performance: "Oxidative DNA damage has been implicated in the aging process and in some of its features such as telomere shortening and replicative senescence. Poly(ADP-ribosyl)ation is involved in many molecular and cellular processes, including DNA damage detection and repair, chromatin modification, transcription, and cell death pathways. We decided to examine the behavior of poly(ADP-ribosyl)ation in centenarians, i.e., those subjects who represent the best example of longevity having reached a very advanced age avoiding the main age-associated diseases. ... Our data show that cells from centenarians have characteristics typical of cells from young people both in their capability of priming the mechanism of repair after [oxidative damage] and in poly(ADP-ribosyl)ation capacity, while in cells from old subjects these phenomena are delayed or decreased. ... Our data support the hypothesis that this epigenetic modification is an important regulator of the aging process in humans and it appears to be rather preserved in healthy centenarians, the best example of successful aging."