Martijn
This is probably exactly why the bioethicists mentioned in the article linked like to talk about this, because the lines are extremely fuzzy I also do not have a stake in this, as I am not a woman. So it is easy to test the borders. An ovum or sperm cell cannot divide, true. On the other hand, cancer cells include evolved (well... changed/mutated, which is arguably what evolution is) DNA, they adapt, and have the ability to grow and multiply.