HMM: SHORT TELOMERES BOOST PROGERIN AGING PROTEIN. “Each time a cell divides its chromosome caps (called telomeres) get shorter. When telomeres get really short they interfere with the health of cells and cell division becomes more difficult. Telomere length is an indicator (albeit not perfect) of cell age and cell health. Therefore mechanisms by which telomere length impact cell health and cell death are as important topic of aging research. So it is interesting that NIH researchers have discovered a mechanism by which telomere shortening boosts production of the toxic protein progerin in cells. . . . You might think, why not rejuvenate by lengthening telomeres? The problem (see that link) is that telomere shortening is probably a defense mechanism against cancer. So lengthening telomeres (assuming we had a treatment that would do this) might not lower the risk of all-cause mortality. However, throw in some great cures for cancer (the sooner the better) and telomere lengthening will suddenly become a very appealing idea. Another possibility: If we could bioengineer our immune systems to very aggressively police against cancers we could reduce the cancer risk from making our telomeres long again. Immune system rejuvenation along with tweaks to make the immune system more aggressive against cancers could so reduce cancer risk that telomere lengthening would carry far less risk.”

Alternatively, people might feel that a higher risk of cancer is worth it compared with feeling old and decrepit.