doing a prolonged fast and or in some cases the fasting mimicking diet causes this massive shrinking of organs where now he doesn't know how much of it's due to cell size decreasing versus apoptosis he does know a puppet apoptosis is occurring and he has showed that in multiple publications like there's a massive induction of apoptosis after a prolonged fest and you know which makes sense because it's a very strong stress and then after during the refeeding phase their organs basically come back they come back they grow regrow and presumably selectively repopulate yes so he's shown that these stem cells get activated