If we have full-on adult genetic modification capable of the, ah, dramatic example you provide, we’ve certainly figured out a way to get around in-vivo test dif

If we have full-on adult genetic modification capable of the, ah, dramatic example you provide, we’ve certainly figured out a way to get around in-vivo test difficulties. For better or worse, any biomedical advance comes up against that problem sooner or later. Therapies to slow aging have the particular problem that it could intrinsically take decades to show an effect, sure- but that’s simply reason to be a bit more ambitious and aim for therapies to reverse aging, which could be tested rapidly in already-old patients. :)