Hypertrophy isn’t the multiplication of cells, but the growth of existing cells.
New cells born in a tissue in four cases, by what I know:
1) when cancer developes;
2) when scar tissue is formed;
3) when tissue is broken (ex. bones);
4) when hyperplasia developes: but hyperplasia phenomenon never has been observed in humans.
So, I’m pretty skeptics that PE is related in someway with those studies.
This is exactly what I’d always believed. To my knowledge, hyperplasia has been observed in felines (amongst other animals), but never in humans.
So, after a human reaches maturity, your first 3 points apply. But skin cells also grow, and we shed our skin (something like once per month - but so gradually, not like a snake. And hair follicles also grow (new cells).
And while the cells in our body *replace* themselves, they do not grow “new” or “additional” cells - not once puberty has ended.