The Methuselah Mouse Prize (MPrize), is the premiere effort of the Methuselah Foundation and is being offered to the scientific research team who develops the longest living Mus musculus, the breed of mouse most commonly used in scientific research. Developing interventions which work in mice is a critical precursor to the development of human anti-aging techniques, for once it is demonstrated that aging in mice can be effectively delayed or reversed, popular attitudes towards aging as 'inevitable' will no longer be possible. When aging in mice is shown to be 'treatable' the funding necessary for a full-line assault on the aging process will be made available. This is the true power of the Methuselah Mouse Prize, to demonstrate a proof of principle, and give hope to the world that decline in function and age-related disease are no longer guarantees, for us, or for future generations, if we work together now.