Strategies for engineered negligible senescence (SENS) is a range of proposed regenerative medical therapies, either planned or currently in development, for the periodic repair of all age-related damage to human tissue. These therapies have the ultimate aim of maintaining a state of negligible senescence in patients and postponing age-associated disease. SENS was first defined by British biogerontologist Aubrey de Grey. While some biogerontologists support the SENS program, others contend that the ultimate goals of de Grey's programme are too speculative given the current state of technology. The 31-member Research Advisory Board of de Grey's SENS Research Foundation have signed an endorsement of the plausibility of the SENS approach. Framework The term "negligible senescence" was first used in the early 1990s by professor Caleb Finch to describe organisms such as lobsters and hydras, which do not show symptoms of aging. The term "engineered negligible senescence" first appeared in print in Aubrey de Grey's 1999 book The Mitochondrial Free Radical Theory of Aging. De Grey defined SENS as a "goal-directed rather than curiosity-driven" approach to the science of aging, and "an effort to expand regenerative medicine into the territory of aging". The ultimate objective of SENS is the eventual elimination of age-related diseases and infirmity by repeatedly reducing the state of senescence in the organism. The SENS project consists in implementing a series of periodic medical interventions designed to repair, prevent or render irrelevant all the types of molecular and cellular damage that cause age-related pathology and degeneration, in order to avoid debilitation and death from age-related causes. Strategies As described by SENS, the following table details major ailments and the program's proposed preventative strategies: Scientific reception While some fields mentioned as branches of SENS are supported by the medical research community, e.g., stem cell research, anti-Alzheimers research and oncogenomics, the SENS programme as a whole has been a highly controversial proposal. Many of its critics argue that the SENS agenda is fanciful and that the complicated biomedical phenomena involved in aging contain too many unknowns for SENS to be fully implementable in the foreseeable future. Cancer may deserve special attention as an aging-associated disease, but the SENS claim that nuclear DNA damage only matters for aging because of cancer has been challenged in other literature, as well as by material studying the DNA damage theory of aging. More recently, biogerontologist Marios Kyriazis has criticised the clinical applicability of SENS by claiming