Abstract
The aging field is replete with theories. Over the past years, many distinct, yet overlapping mechanisms have been proposed to explain organismal aging. These include free radicals, loss of heterochromatin, genetically programmed senescence, telomere shortening, genomic instability, nutritional intake and growth signaling, to name a few. The objective of this Point-of-View is to highlight recent progress on the "loss of heterochromatin" model of aging and to propose that epigenetic changes contributing to global heterochromatin loss may underlie the various cellular processes associated with aging.