This makes tremendous sense on all kinds of levels. As long as you have a stem cell population, eliminating senescent cells will trigger their replacement. Whe

This makes tremendous sense on all kinds of levels. As long as you have a stem cell population, eliminating senescent cells will trigger their replacement. When you think about it, reproduction and the birth of a new human being is an extreme example of this. Start with one pristine fertilized egg cell and build a whole new body. This does lead to a related question though: what the heck goes on in germ-line cells that keeps them 'immortal' like this? Of course whatever it is maybe it's something that is mutually exclusive with what has to happen in body cells after they differentiate. Maybe germ line cells just keep most of their DNA "offline" and more or less keep themselves pristine by not doing anything.