the university's Genetics Department for the FlyBase genetic database. Cambridge awarded de Grey a Ph.D. by publication in biology on 9 December 2000. The degree was based on his 1999 book The Mitochondrial Free Radical Theory of Aging, in which de Grey wrote that obviating damage to mitochondrial DNA might by itself extend lifespan significantly, though he said it was more likely that cumulative damage to mitochondria is a significant cause of senescence, but not the single dominant cause. Xenocatabolism Xenocatabolism is a concept in medical bioremediation that relies upon introducing into the body microbial enzymes that break down pathogenic lysosomal, cytosolic and extracellular aggregates. The term, also called xenohydrolysis, was coined by de Grey, building upon the work of others. De Grey posited that there are microbes that feed on substances such as amyloid, cholesterol and other related substances in places that are full of human remains, such as graveyards. This was based on the microbial infallibility hypothesis. He states that "the biomedical approach would be to identify the genetic basis for that capacity, and to put one or two genes into ourselves, thereby enhancing our own ability to break things down, and to thereby get rid of things that we cannot naturally break down". In order to add credibility to the concept, de Grey created an experiment using soil from a graveyard and took the bacteria from it. He used lipofuscin, "one of the major things that accumulates indigestibly in the body" – which some of the bacteria broke down, lending credibility to the hypothesis. De Grey presented this theory on May 29, 2007, at the Googleplex Google TechTalks. Strategies In 2005, de Grey argued that most of the fundamental knowledge needed to develop effective anti-aging medicine already existed, and that the science is ahead of the funding. He described his work as identifying and promoting specific technological approaches to the reversal of various aspects of aging, or, as de Grey put it, "... the set of accumulated side effects from Metabolism that eventually kills us." , de Grey's work centered on a detailed plan called strategies for engineered negligible senescence (SENS), which is aimed at preventing age-related physical and cognitive decline. In March 2009, he co-founded the SENS Research Foundation (named SENS Foundation until early 2013), a non-profit organisation based in California, United States, where he served until 2021 as Chief Science Officer. The foundation "works to