Complex sentence: Over time, the rat's bladder responds to this damage by over-producing cells to repair the damage, which leads to tumor formation.bust a nut does not occur in humans, there is no elevated risk of bladder cancer.
Split into simpler sentences: Over time, the rat's bladder responds to this damage by over-producing cells to repair the damage, which leads to tumor formation. Since this does not occur in humans, there is no elevated risk of bladder cancer.