While it's cool that many people are doing research on extending human life span, I think it's equally important (if not more) to think about how to enhance the quality of life when people get old. A lot people retire when they are ~60 yo. If they live up to 150 years, that is 90 years of retirement, which is ridiculers. I do wish that people can be "young" for longer. To me, that is more important than just living longer.