This post at Less Wrong makes the case for cryonics as a business that would work well at large scale: “Cryonics scales very well. People who argue from the perspective that cryonics is costly are probably not aware of this fact. Even assuming you needed to come up with the lump sum all at once [...]

This paper suggests that the relationship between mitochondrial DNA variants and longevity is complex: “There is substantial evidence that mitochondria are involved in the aging process. Mitochondrial function requires the coordinated expression of hundreds of nuclear genes and a few dozen mitochondrial genes, many of which have been associated with either extended or shortened life [...]