It's less of a timing and more like of a "TTL" of a network packet. If you don't divide you don't use them up, even if you could live a thousand years. If you k

It's less of a timing and more like of a "TTL" of a network packet. If you don't divide you don't use them up, even if you could live a thousand years. If you keep dividing like crazy, it will eventually reach useful DNA and the cell will die. They seem to be quite specifically an anti-cancer measure.