Aubrey de Grey, a software engineer, devoted himself to studying the biology of aging and sparked debate with his radical views. In October 2000, he helped organize a roundtable on engineered negligible senescence (SENS) strategies, hosted by biochemist Bruce Ames. The participants were eight scientists, including established biologists in the field of aging. The discussion ended with the optimistic conclusion that a combination of existing or foreseeable biotechnologies, such as stem cell transplantation, will enable the reversal of aging in mice within 10 years[1]. Participants hypothesized that similar achievements would occur in humans shortly thereafter, decades later[1]. De Gray wants to wake up the gerontological community, which he considers too cautious, and calls for recognition of the possibility of slowing down aging or rejuvenating bodies[1]. In 1996, he proposed a theory of the accumulation of mitochondrial DNA (mtDNA) mutations that cause oxidative damage leading to aging, and a solution through gene therapy to replenish enzymes in lysosomes from soil bacteria[1].