> Yet attempts to increase health and lifespan have been successful in nearly every animal studied so far. In a 1993 study, changing just one gene (daf-2, a pat

> Yet attempts to increase health and lifespan have been successful in nearly every animal studied so far. In a 1993 study, changing just one gene (daf-2, a pathway humans share) in C. Elegans worms doubled their lifespan. Changing one additional gene (rsks-1) resulted in a five-fold lifespan increase—the equivalent of a 400-year-old human. In mammalian models, approaches like inhibiting mTOR activity or eliminating senescent cells often result in increased function and median survival rates. > Technologies like genome engineering for polygenic conditions may be decades away from safety, and a long list of scientific and technological bottlenecks remain underfunded. In addition, because clinical trials for multiple disease indications are also costly, lengthy, and prone to false-fails, the effects of existing therapeutics on human aging remain largely speculative.