They can cooperate with one another to basically either release or bind that oxygen manner, that oxygen molecule in a cooperative fashion. Now, what this means physiologically, as I said earlier, it makes the hemoglobin a great carrier of oxygen. So what that means is at the lungs, when our hemoglobin is in the lungs, it can easily bind that oxygen. But when it gets the cells and tissues of our body, it has no problem actually unloading and releasing that often to the cells of the tissues of our body. So we conclude that myoglobin does not bind oxygen cooperatively. And this basically makes it a great storing molecule.