I'll be perfectly honest though: The only reason I support pursuing research into biological immortality is because I highly doubt that it's actually medically possible. Extended human lifespans and improved quality of life/slowed aging I'm sure are possible. But bodies are going to wear out, no matter what we do. And bodies will always be subject to accidental injury no matter what we do. I think the chances that we'll be able to fully regenerate or mitigate accidents and simple wear and tear are pretty low. (I honestly think the chances that we'll completely eliminate infection is also pretty low. Bacteria and viruses are just smarter and faster than we are.)